I found this 2002 E46 M3 on eBay and the owner has spent a lot of time and money converting it into a dedicated race car.
Braking is critical on a race car and this M3 is outfitted with a set of front and rear Performance Friction calipers that use a huge 14″ front rotor with 13″ rear. Bimmerworld carbon brake ducts help keep the braking components cool and direct air towards the large calipers without adding much weight to the car.
The suspension is setup with a JRZ RS double adjustable dampers with hypercoil springs. Ground control camber plates and bushings are used to keep the steering feel firm with less deflection from the higher durometer parts.
The exterior of this M3 is all business with a huge Bimmerworld V2 wing in the rear and cool looking dive planes on the front. The rear diffuser is a huge carbon fiber piece and is produced to work in conjunction with their exhaust system.