Originally Posted by Petros
Perhaps, but if you really want a dedicated race car then an M3 is a subpar platform for that. It's quite expensive, and for all that cost it's still underpowered, overweight, and requires a long laundry list of mods before being ready for racing. It's not a particularly fast car for the money either. For such a price tag there are many platforms that are more suited for building a race car, for example a slightly used C6 Z06, Cayman R, GTR, or even a Boss 302.
I'd agree for a track day car but things are a lot more complex when it comes to club racing which my previous post was directed at. BMWCCA, SCCA, and NASA all have classes for M3s which don't allow some of the cars you mentioned. And GTRs are expensive to track (fuel, tires, brakes,..)