Newbie FAQ: Sent by DiscoKid

Much of the content below has been presented thanks to Kevin Liu.  If you have any more additions please copy this page and add the new content, then email it to me at



Where is my amp?

On the left side of the trunk behind fold down panel. It is anodized black with heatsinks at the top. 

How do I set my DSP?

Tips on how to set your DSP can be found here:

DSP Settings

Where is a pin diagram of the amp connector?

The pin diagram for premium sound can be found here: 

 Wiring Diagram

What is the difference between DSP and non-DSP?

The DSP system is the same as the stock system but adds the following equipment:

- Bandpass subwoofer enclosure mounted under the rear shelf. The enclosure contains two 5.25" woofers.

- Amplification for the above subwoofer

- Additional signal processing modes and a 7 (?) band graphic equalizer. The non-DSP system has only Bass and Treble controls.


Can I add aftermarket amplifier(s) to the stock head unit?

Yes. The stock head unit provides 4V pre-amp level outputs and interfaces well to most aftermarket amplifiers. A wiring diagram of how to do so can befound here:

What CD changers and adapters can I use in my E39?

A variety of CD changers are available for the E39. BMW offers a Nakamichi glove box changer and an Alpine trunk changer. Both are direct bolt-in’s and require no adapters. The Nakamichi does require rewiring of the CD changer cable, however, and install is costly. These changers can be bought at any BMW dealer. You will also need a metal bracket – part #   .

            Your other choice is to add an aftermarket CD changers and use an adapter. Alpine CD-changers can be added with an adapters made by a handful of different companies. Adapters range in price for 50-200 based on quality. Some have reported that using inferior adapters has caused the MID to blink and eventually die.

 You can get the official BMW changer.  If your car doesn't have the navigation system, yes. The part number is 65128387323. Cost is ~$550.

What size are my stock speakers?

The stock woofers are 5-1/4” all around. Non-premium sound systems have 10 speakers. Two woofers in the front door, two woofers in the rear deck, one tweeter on each door, and two tweeters near the a-pillars. Premium sound systems adds DSP and two additional speakers in the form of Nokia 5 ¼” subwoofers in a bandpass enclosure underneath the rear deck.

What is the difference between DSP and non-DSP?

The DSP system is the same as the stock system but adds the following equipment:
- Bandpass subwoofer enclosure mounted under the rear shelf. The enclosure contains two 5.25" woofers.
- Amplification for the above subwoofer
- Additional signal processing modes and a 7 (?) band graphic equalizer. The non-DSP system has only Bass and Treble controls.

Can I add aftermarket amplifier(s) to the stock head unit?

Yes. The stock head unit provides 4V pre-amp level outputs and interfaces well to most aftermarket amplifiers. A wiring diagram of how to do so can be found here in the tips section

What are some options for adding a subwoofer?

 What are some options for adding a subwoofer?

There are two types of subwoofers that can be added: a sealed enclosure placed in the trunk, or a free-air (infinite baffle) installation of subwoofers mounted underneath the rear shelf. A short discussion of the merits of the three main types of sub enclosures is presented here.

A ported box and sealed box of the same size would give you intrinsically different sounds. Ported boxes can be easily tuned by changing the port size to give you the frequency response you want. In general, a properly tuned ported box will give you better efficiency than a sealed box because it can be tuned to produce maximum volume near specific frequencies. A sealed box will generally give you tighter and deeper bass extension but at the cost of efficiency. A band-pass box will give you maximum efficiency over a very narrow range of frequencies. It will generally be the loudest but also the loosest and have the sharpest roll-off at low frequencies.

Notice I said generally. Any of the above box types can sound equally excellent given the proper tuning. The sealed box is the easiest to design while the band-pass is the most difficult. Another option is free-air or aperiodic. These types of systems mount woofers directly to baffles with no boxes. It is essential however that the front and rear of woofers are separated such that sound waves propagating from opposite sides do not meet and cancel. Free-air installations generally offer very good low bass extension but poor efficiency. Common free-air installations involve mounting baffles parallel to the rear seat back or underneath the rear package tray and subsequently mounting woofers to these baffles. Subwoofers used in free-air installations must be specifically designed for free-air applications so that they posses the proper damping to compensate for the lack of a box. Common subwoofers can be used in free-air applications with the addition of an aperiodic membrane.

Now about box size. Box size is critical in tuning your subs. it is just as important if not more important than the woofers you choose. Speakers have parameters called

Thiele-Small parameters that characterize their sonic behavior. Given these parameters and different box volumes a Q-value can be calculated for each box-woofer system. Sub systems with low Q tend to have deeper, bass extension and tighter bass but need large boxes. Sub systems with high Q's need smaller enclosures, are more efficient but have narrower bandwidth. Much like in a circuit. These parameters can be modeled with simple computer programs. Thus, you can design your subs around the kind of sound you prefer and the music that you listen to by tailoring the q-value and resonant frequency of the entire system.



What upgrades do the sport packages add to the suspensions?

528 Sport package adds 3-spoke steering wheel, 17” wheels, shadowline trim, and upgraded sport suspension.

540 sport package offers 3.15 rear axle and torque converter, sports suspension, 17” wheels, shadowline trim, 3 spoke steering wheel and sport seats.  some options differ through the years. 

What springs are available for 528/540?

Springs are available from Eibach, H&R, AC Schnitzer, Racing Dynamics, RMS, etc. Most lower the car about 1”. A few coilover kits are also available but are very pricey.

 What shocks are available for 528/540?

Shocks are available from ACS, RD, Bilstein, Hamann. The stock shocks are Sachs units. Shocks are pretty much the most important component of the suspension when it comes to handling, more so than lowering springs. 

Do I need new shocks when I lower?

It really depends on how much you lower your car and what your goals with the car are. Shocks are more important to handling than springs are. If your goal is to increase handling and sharpen cornering then shocks are a must. The ride will get a little rougher with the addition shocks and springs. If you don’t lower the car a great deal, the stock shocks will probably be able to handle the job. The problem comes when you drop the car a great deal and retain the stock shocks. This causes the stock shocks to operate outside their optimal range of travel and shortens their life. In addition, with stiffer springs the stock shocks may not have the correct valving to properly damping the increased spring rate. It’s always a good idea to change shocks with springs but the stock sport shocks are probably ok with mild lowering.


What are strut tower braces and who makes them?

Strut tower braces are usually metal braces that span across the front and rear shock towers to reinforce the body and increase overall rigidity of the body. Typically, the have metal rings on the end and mount to the same bolts that hold the shocks on. STB’s prevent the shock towers from flexing under heavy suspension stresses in order to increase handling and preserve correct suspension geometry under spirited driving. Plus, they look cool.


What are sway bars and who makes them?

Sway bars mount on the bottom of the car and serve to tie the lower ends of the left and right sides of the suspension together. Thick sway bars tend to decrease body lean during cornering and decrease grip at the end of the car that you install them on. For example, if you have a car that has a mild understeer, as most cars do, adding a thicker rear sway bar will cause the rear of the car to lose grip and come around sooner. Thus, the car will now corner flatter and become more neutral. Front bars cause cars to push more and rear bars cause cars to oversteer more. The effect is similar to increasing the overall spring rate on that end of the car.


What are the stock tires?
E39’s came from the factory different brand tires based upon the date they were made. Sizes are the same at all for corners unless otherwise specified. Factory tires are Dunlop SP2000E, Continental Sport-Conti,
528i non-sport – 225/60R-15
528i sport – 235/45R-17
540iA non-sport – 225/55R-16
540i 6sp- 235/45R-17(fr), 255/40R-17(rr)
Given a wheel size such as 225/60R-15: 225 refers to a wheel 225mm in width, aspect ratio of 60 and radius of 15. Many times a speed rating is also indicated before the R such as:
QR 100 mph HR 130 mph
RR 106 mph VR 149 mph
SR 112 mph ZR over 149 mph
TR 118 mph WR 168 mph
UR 124 mph YR 186 mph
Aspect ratio describes how thick the sidewall of the tire is relative to the tire width. A tire with a width of 225 and an aspect ratio of 60 would have a sidewall height that is 60% of 225mm or 5.3 inches.

What are the stock wheel sizes?
Stock wheel sizes are:
528i non-sport – 15x7.0
528i sport – 17x8.0
540iA non-sport – 16x7.0
540i 6sp- 17x8.0(fr), 17x9.0(rr)
In each case, the first number refers to the wheel diameter and the second number refers to the wheel width.

What is my stock offset, center bore, and bolt pattern?
Stock offset, bore, and bolt pattern are +20 mm, 74.1 mm, and 5 x 120 mm. The bore and bolt pattern of your new rims must match the stock specifications in order for your rims to mount on the hub correctly. The offset can be variable over a reasonable range. Offset describes how far the hub mounting surface lies from the centerline of the rim. A more positive offset pushes the wheel farther towards the outside of the car. A more negative offset pushes the wheel closer towards the middle of the car. The offset can be varied as the rim width changes to ensure that wheels will clear suspension components on the inside and not rub the fender on the outside. For a diagram and a more detailed discussion on offset visit this site It is Eclipse related but informational nonetheless.

What are the smallest rims that will fit my car?
The smallest rims that will fit your car are basically the smallest rims that will still clear the brakes.

What are the largest rims that will fit my car?
The largest rims that will fit on your car will depend upon your suspension modifications. With a car lowered about 1” all around, the largest rims that will fit are roughly 8.5x19 front and 10x19 rear. The tires to go with these rims are 245/30R-19 and 275/35R-19 respectively. This will definitely require rolling the rear fenders. It is also possible to go with a slightly wider rim in both the front and the rear so long as the tire width and aspect ratio does not change. With a stock suspension, it is possible to fit a 20” rim, but you may not be able to go as wide in the rear.

What size tires should I put on my rim?
Generally, the tire should be within ±15% of the rim width. The tire cannot be either too wide or too narrow to in order to seat properly. Thus, an 8” rim could utilize a tire between a 175-235mm. Plus sizing should be used to choose tire aspect ratio. For each inch that the wheel increases in size, the aspect ratio should decrease 10. This allows the sidewall height to decrease as the rim increases in diameter to maintain a roughly constant outer diameter. A car with 55R-16 could increase to a 45R-17 or a 35R-18, roughly, without increasing in diameter. To be exact, you can calculate the exact outer diameter by utilizing the aspect ratio to find sidewall height, multiply by two, and add to rim diameter to find more accurate tire height.

When do I need to roll the fenders?
Many times when upgrading to larger rims, the tire will start to rub the fender as the suspension travels upwards. The inside of the fender has a small lip that protrudes inwardly and perpendicularly from the fender at 90°. It protrudes about 1 cm. This lip can be folded or rolled flat against the fender so that another 1 cm of clearance is created. Rolling the fender is a literal term taken from the way that most people accomplish the task. The car is jacked up, the thick end of a baseball bat is placed between the wheel and the fender, and the car is lowered back to the ground. The car is slowly rolled forward and backward and as pressure is placed downwards on the handle of the bat. This exerts an upward pressure on the lip and causes it to fold backwards against the fender. It sounds archaic, but this is still the main way it’s done. People often accomplish this task with a 2x4, hammer, or any other blunt weapon. For a more civilized approach, Snap-On offers a nylon roller on a metal arm that attaches directly to the hub.

What is the reasoning behind staggered tires?
Rear wheel drive cars often run larger wheels and tires in the rear than the front. This is often done to maximize rear traction in high horsepower cars. It is not detrimental to the car at all. Some claim it is done to minimize oversteer as well.


Who makes exhaust systems for my car?

Bolt-on exhaust systems are made by many tuners. Some of the more popular systems include Remus, Supersprint, Schnitzer, RD, etc. Check next link for more details.

click here

Why do I want one?

The purpose of an exhaust system is to increase flow and decrease back-pressure. Increasing the ease for exhaust gases to exit the car also makes it easier for intake air to enter the engine. The greater the volume of air you can get through your engine, the more power you can make. Oftentimes, though, a little bit of back-pressure is good and an exhaust that is too free-flowing will actually cause a loss of power, especially on small-displacement normally aspirated engines. On forced-induction applications, bigger is better. One of the “side effects” of larger pipes is an increased exhaust note.


What are headers?

Headers refer to the equal-length runners in tuned exhaust manifolds. The purpose of equal length exhaust runners is so that the exhaust pressure waves exiting each of the cylinders travels exactly the same distance. This helps facilitate gases to exit by ensuring that the pressure waves sum correctly at the collector. Scavenging sometimes also helps “draw” exhaust gasses out. Headers have many different designs with various runner and collector arrangements.


Who makes a short shifter for my car?
AC Schnitzer, IntakeMetric Mechanic/Auto Solutions, Korman, Blonde Motorsports, UUC,AutoThority, Active Autowerke

What is a CDV?

It stands for Clutch Delay Valve and it is used to restrict hydraulic fluid to the clutch supposedly making for smoother (slower) clutch engagement.  BMWs original though was to reduce the torque that a accidental clutch drop might transfer to the differential.  Many have removed it.  For more info click here  

Who makes clutches for my car?

Only Dinan so far.

Who makes intakes for my car?

Intakes are available from many companies and come in many forms. Some simply replace the stock box with an adapter and a cone filter ala K&N. Others replace the entire intake track up until the throttle body by providing new, larger intake piping. Yet other models route the air intake to the front bumper and fender area so there is direct access to cool air from outside the engine compartment.

What is a CAI and do I need one?

A cold air intake is designed to reduce intake restrictions so that air enters the engine more easily. This is often accomplished by increasing overall filter area via a cone filter versus the stock rectangular filter and eliminating the air filter box to allow a more direct intake path. But this can expose the intake hot air from around the engine which will decrease horsepower. To make power, we need large amounts of cool, dense air. To solve this problem, make people either relocate the entire filter assembly to the fender well area or box off the filter and run a hose to the fender or bumper. In this manner, cold air can be drawn in from outside the engine compartment without the restrictive stock box.


Where can I get a larger throttle body?

After replacing the intake track, the throttle body often becomes the next most restrictive portion of air flow. A throttle body is basically a small tube with a flat plate inside that can be flapped open or closed as the throttle is applied. A larger throttle body is often simply a bored out stock unit with a modified (larger) throttle plate. Other more elaborate units are entirely new.



Who makes superchargers for my car?

            Superchargers for 528-RMS

           Superchargers for 540-Dinan,


Who makes turbochargers for my car?

            Turbochargers for 528

            Turbochargers for 528


Who makes stroker kits for my car?

            RD is the main manufacturer of stroker kits for the 540.




Who makes engine chips for my car?

            Chips are available from Jim Confortti, AC Schnitzer, Racing Dynamics, Dinan, Autothority,


What is OBD-II?

Here is a government site explaining OBD-II It’s basically a diagnostic system that the dealer can use to access information about the car. Error codes and malfunctions as well as access to various sensors, programming, etc can be can be accomplished here.




What is the part number for the M5 Front Grille?

The M5 Grille has a larger chrome surround and chrome plated slats.

51-13-2-497-261 Left

51-13-2-497-262 Right


What is the part number for the front license plate strip?

Non-sports need both of the following parts:

51-11-8-226-559 Chrome Strip

51-11-8-226-565 Black Rubber Strip

Sport model needs only the following (no chrome strip, only black rubber strip):

51-11-8-174-850 Black Rubber Strip

The parts are not identical. Be sure to order the correct one.


Can I replace the rear cupholders?

You can replace the rear cupholders with a small storage bin. The part number is 51 168 159 701 and lists for $8.90.


Can I replace the armrest?

Yes, you can replace the hard plastic armrest will a padded rubber armrest that has a storage bin. It does not compromise the rear circulation. Here is more information armrest


Can I install a radar detector on my 5?

Yes. Here is a link of how-




What are stock bulb sizes?


Xenon -?

Halogen -?



What do I need to retrofit >01 lights on <01?

The updated angel-eyes can be retrofitted on pre-2001 e39’s with kits available from Hella or with parts purchased directly from a dealer. The Hella kit uses OE parts and is the simplest way to go. Both xenon and halogen upgrades are available. The rear crystal LED style lights can also be retrofitted with a little work. Don’t expect this upgrade to be cheap.


What do I need to install BMW Xenon’s?

Upgrading non-Xenon E39’s to Xenon is a complicated process. It involves changing to the xenon lenses, adding lamp ballasts, and auto-leveling system.


What are Jimmy Xenons?

Jimmy Xenon’s are basically xenon-look halogen bulbs. They are typical halogen bulbs that may contain trace amounts of xenon gas but are not true xenon high intensity discharge systems. Most of these types of bulbs attempt to simulate the xenon look by using colored class to give the light a more bluish-white tinge. Some are more realistic than others. Check here for more details 


Where can I get clear lenses? Are they legal?

Clear lenses are simply the European version of the E39 lights since most European cars use clear lenses. Clear lenses are legal so long as the bulb inside remains amber in color. Your turn signals and side markers must remain amber.


How do I aim my lights?

Check out this link




What is Euro Delivery?

Euro-Delivery FAQ

What are good dealers?

What is a good price?

What should I expect at delivery?





What are all these squeaks and rattles?

The door seals and fold-down rear seat on E39’s are notorious for squeaks and rattles. Look at this great link from member Jim Cash for more info.


Can I replace the dash trim?

Dash trim is available in wood (PP), gloss black, gloss grey, gloss beige, and aluminum (M5). It is possible to change the trim with OE BMW parts after the fact but is very costly. Aftermarket kits can be considerably cheaper. Beware of fit and quality.


Leather vs. Vinyl?

Premature wear of the leather is a common complaint in E39’s, especially is cars with black leather. Some people have recommended choosing vinyl upholstery rather than the leather.


How do I take car of my leather?

Leather should be periodically oiled with a protectant so that it retains its moisture. Dry leather is more prone to wear and cracking. A popular leather protectant is Lexol.



What wax should I use?

Is a buffer bad for my car?




Who provides good service?

Should I expect a loaner?

When should I do what service