During a recent road trip, I noticed 100 (ok - 50) dead grasshoppers in the passenger front well alongside the fog light. When I got them out, there was no opening - just a sealed off black plastic box. The driver's side well has 4 openings which appear to cool off the driver's front brake.

There appears to be a small plastic rectangle of 3" by 4" held on by 4 clips that can be changed in the back of each well. Why is there no vent on the passenger side?

New M3 owner - sorry for what may be a stupid question. At the very least, it seems strange to have a sealed off box that collects water/debris and creates air resistance.

Just take them both out...

Leave the drivers side in, otherwise the snorkel to the airbox will be getting less air and thus you will be making less power. You can take the passenger side out without worry but it is doing little to cool your brakes...

I'm with Kevlar...take them both out. While it is true you will be making .0001 less HP, the E46 M3's weakness is not the engine, it is the brakes. I've gone through a bunch of rotors (but that has been on the track, not around town). I leave the vents out in the summer, and pop them back in for the winter, just to keep winter crap out of the brakes.

Take them out, leave them out. And don't drive in the snow. :)

Actually the E46 M3 really needs a full brake ducting kit for serious track driving.

I am more curious than anything else. Each side has a removeable 3" by 4" plastic panel inside the black box that opens to the wheel well. The driver's side has the air intake but also has the panel with slots cut into it. The passenger side has the panel without slots.

Why are they there in the first place? Why are they removeable? Are these little panels there for shipping purposes or for access or simply for racing? Why does the driver's side have the slots but not the passenger's side. I stopped by the dealer and the mechanics verified that all M3s were set up that way but had no idea why. The head mechanic thought is was DOT regulations.

Again, this is just me wondering why something this simple was designed this way.

Except for an in-dash CD player that will play a particular CD one day and ignore it the next (dealer has a new one on order), I love my M3 as is.

I believe Euro cars don't come with those two panels installed... I think they only come on US cars.

Take them out, leave them out. And don't drive in the snow. :)

Actually the E46 M3 really needs a full brake ducting kit for serious track driving.

I disagree, and agree....

No reason not to drive the M in the winter. Mine did just fine this winter, with 330i Sport Package 17" wheels (they clear the brakes) and Blizzaks. I put the vent covers over the brake ducts, and there was no issue, other than a bit of restraint with the "fun" pedal. Runs the same as any other car in the snow.

I have the bimmerworld brake ducting setup on the car, and am still getting pad deposits with race pads (started with stock = deposits; moved to Ferrodo DS3000 = deposits; now on Cobalt VR Spec = deposits). I'm moving to AP Racing brakes before the next event. The high speed tracks around here are the problems (Nelson Ledges and BeaveRun). Mid Ohio is usually not a problem, unless it's ungodly hot.

I wish we had an answer why those covers are in there....no way is it a DOT requirement - they don't get into issues like that. It is 1 of about only 6 differences between Euro and NA M3's. Others are:

Front bumper reflectors (now that is a DOT requirement)
Brake ducting
X-drilled rotors
Different SMG Software
Different cat/header design
Different options (DAT player/some color and upholstery/flip-up mirrors)
Different standard equipment (1st aid kit and warning triangle)

That's it.

I recall that northern states (those of us who have snow) get the little brake duct covers while southern states do not. Or was it dependent on whether the car was equiped with the cold weather package? (heated seats, etc.)

Can any southern M3 owners confirm/deny this?

I disagree, and agree....


The not driving in the snow was a JOKE. :)

The first aid kit and warning triangle are requirements in many Euro countries. All cars in those countries have them. We don't get them because the first aid kit has dated items. And the Euro triangle does meet DOT specs for standing up in a wind. But their are sources, I have both.

The headers/cats are because of cold start emissions. Give the Europeans a few more years and they will have them too.

Different SMG software, only the launch control RPM, and due to idiot Americans burning up clutches and claiming it was BMWs fault.

Euro rotors are not on our cars since they make more noise. BMW NA didn't want to deal with the warranty claims of idiots with "noisy brakes." Self defense. Look at the number of people who don't know about proer break in (in manual and even on windshield sticker) or don't check their oil, or tire pressures.

Brake ducts, not quite sure why we get the plugs, except most Germans think we still have a 55 MPH speed limit and that we actually abide by it . :lol:

Different ooptions, that is up to BMW NA and what they think will sell. How many people in the US would buy DAT? How many people know what it is? :)

My car was delivered to S.Florida ... came with brake duct covers. I removed them on the dealership floor.

Most brake systems require some heat in order to function properly. Cold brakes don't work as well as ones at the proper operating temperature. I would assume our M3 brakes are no different. As such, the duct covers help keep the brakes "warm" for daily driving. I doubt most of us drive hard enough on the street to keep the brakes warm. I'd pull them out at the track, but for around town, I leave them in!

Not necessary, the compound that comes equipped on the car is primarly a street compound and works well from ambient temperatures starting well into lower temperatures that would prevent us from going outside.

Not necessary, the compound that comes equipped on the car is primarly a street compound and works well from ambient temperatures starting well into lower temperatures that would prevent us from going outside.

Kevlar, that's a good point. I never thought about the pad compound.

I guess I'm just as stumped as to why those covers are there, now...