People often ask me what sorts of modifications I've made to my car, as (1) I generally don't go out of my way to discuss or list such things, and (2) I'm known as a something of a proponent of the idea that the car is just about right "as is" when is rolls out of the door at Regensburg. 

It's a fair question.  What follows is my fair (if not especially brief) reply.  In the list that follows, I'll give you a 101-level primer on the Chief's personal modifications, along with a few related "how and why" insights.

CUSTOM PAINT (OEM)

As it turns out, my first modification really is no modification at all; at least, not in the conventional sense.  In accordance with the terms of the BMW Individual program, I opted for a non-standard paint color (Velvet Blue Metallic) from the factory.  I've discussed this elsewhere, so I'll not expand upon it here.
 

EURO BRAKE ROTORS  & PADS (OEM)

Most owners realize that the M3 receives a bit of "smoothing over" for the U.S. market.  One of the most obvious differences lies with the brake rotors supplied on the U.S. machine.  Now, contrary to popular opinion, the non-drillled U.S. rotors do provide every bit as much clamping force as the Euro market drilled (cast) models.  Where the latter have an advantage is in the area of fade resistance with prolonged usage; a condition somewhat more relevant to the tracks and autobahns of Europe than to the highways and byways of middle America.  Still, given where I am, and how I am subsequently able to drive, this is something of a mandatory upgrade in my book.

EURO CONSOLE ROLLTOP STORAGE BOX (OEM)

Cupholders?  I buy a 340 horsepower Porsche-killer, and they give me cupholders?  This concession to convenience, standard only in the U.S. version of the car (to the best of my knowledge), was removed before I even drove off away from the dealership.  The Chief don't need no stinkin' cupholders ... besides, the rolltop unit that comes standard on the Euro version of the car strikes me as an infinitely more refined and useful storage solution. 

P7 SMG II BRAKE PEDAL (GSP)

If I could only add one modification to my car, this would be it.  No, it isn't OEM.  No, it isn't cheap, or even wildly popular.  Still, if you own a SMG II equipped car, this is probably the single-greatest performance (and convenience) modification that you can make to your machine.  Full-time, hard-use left foot braking is the name of the game, and nobody gives you a better tool for doing it than GSP.  For me, the P7 is simply a must-have piece of equipment -- even at twice the price.

M3 CSL WHEELS (OEM)

I started working on CSL wheels rather early; or at least, well ahead of the popularity rush that we saw in the middle of 2004.  Appearance was an issue for me, but my real objective in going to the CSL wheels was to reduce weight and to facilitate a tire upgrade to the OEM CSL sizing.  Many months later, the ZCP option made getting a set of these BBS-sourced wheels a more attainable goal for non-CSL owners (notwithstanding the half-inch front width difference between the CSL and ZCP models).  While these wheels are somewhat prone to chipping and other minor contact damage, most owners agree that the look and weight benefit make them a worthy upgrade.

PILOT SPORT 2 TIRES (OEM, MICHELIN)

See above for rationale.  I tend to stick with OEM manufacturers here, too, so the only rubber you'll likely ever see under my car (with the possible exception of snow tires) are Continental ContiSport Contact 2s, Michelin Pilot Sport 2s, or Michelin's ferocious R-compound Pilot Sport Cups.  Presently, I'm running on PS2s in the correct OEM CSL (235/265) fitment.

WHEEL LOCKS (OEM)

$3,500+ worth of protection for about $35 worth of investment.  Need I say more?  Put one lock in your trunk lid tray, and one in your toolbox at home.

M3 CSL DIFFUSER (OEM)

I'm anti-bling in most every sense of the word, but I'm not going to try to convince you that my primary purpose here was to achieve an actual performance benefit.  A friend extended a very generous offer on an OEM diffuser, and it seemed positively foolish to pass up the opportunity.  Now, it is quite true that there is an aerodymic difference between the CSL and the standard M3 (-20 lbs of rear axle lift reduction versus +36 lbs of lift at 125 mph), but I'm fairly certain that the full advantage afforded by the diffuser is only realized in conjunction with the CSL front splitter/apron.  Still, anything I can do to improve the high speed stability of the car -- even slightly -- is a good thing.  I'm not about to modify the entire car's aero package, but I have to admit that the diffuser makes me happy for some reason.

BODY-COLORED FRONT REFLECTORS (OEM, evosport)

Like most American M3 owners, I've never been too crazy about the DOT-mandated amber front reflectors on our cars.  On my way back from Iraq, the boys at evosport made me an offer I couldn't refuse, and they did a great job of properly matching my car's BMW Individual body color in delivering a top quality product.  I'm not sure these are giving me that all-important 3-5 horsepower boost, but I'm enjoying them just the same. 

AUXILIARY INPUT CABLE (OEM)

I'm still not sure why this wasn't a standard feature on later M3s, but for those who aren't particularly interested in losing their CD changer capability (or in being restricted to using an iPod), the stereo AUX input is a great alternative.  This is another fairly straightforward DIY project that will reward you quite nicely for minimal expense and effort.  Just remember to plus-up the AUX input volume on your radio control head, as the default setting (3?) is going to be on the low side for most MP3 players.

REMOVAL OF BRAKE DUCT COVERS (OEM)

Not a modification, per se, as my car didn't actually have these covers in place to begin with.  Nevertheless, I bring it up for general awareness, as many U.S. owners are unaware of the situation.  If your brake duct tunnels are partially (left) or totally (right) blocked with plastic cover plates, the good news is that these are easily removed.  Keep in mind, however, that in a heavy downpour your brakes are now much more likely to be waterlogged, so remember to tap the pedal every now and again if you're doing any extended highway cruising. 

As an aside, let me confirm that there is no truth to the oft-repeated rumor that BMW installed these in response to a lawsuit.  The BMWCCA chapter article that generated all of this "small mammals in the brake ducts" foolishness was intended to be a tongue-in-cheek example of why BMW changes some of the things that they do on U.S. versions of the car.  Nothing more.  It never actually happened.

TRUNK NET (OEM)

Say what you will about these things being rather overpriced; I wouldn't even think of going without one.  The net allows you to drive however you need (or wish) to, without worrying about finding the contents of your various parcels, bags and boxes strewn all about the trunk after you arrive at your destination.  I know there are some worthy aftermarket alternatives out there, but this is an essential piece of kit in my estimation.

BLUE TINTED CORNER LIGHTS (OEM)

I wasn't particularly concerned about the subtle amber hues reflected in my corner lights during the daytime (i.e. when the bulbs aren't illuminated), but my German parts guy informed me that this was a grave faux pas in the world of local automotive fashion.  Since he then went on to offer me a nice discount on the blue-tinted (and still OEM) variant, I didn't even bother turning him down.  Bling, bling.  OK, you got me.  There are probably three people in all of Hessen that would even notice this, but I'm sure they are duly impressed.

That about covers the list for now.  I've been having DSL difficulties all week, and haven't really been able to get to the "modifications under consideration" list; perhaps that will give you something to look forward to.  Nor, for that matter, have I forgotten about the 'Ring training feature I promised back in October.  All in due time.

See you back here (hopefully) soon!