[Bumpinjeep]

I think the idea of tracking a new M car is cool, especially if you're not really racing it or trying to set lap times. If you're having fun, that's a different story.
If you're trying to get the most out of it and chasing time, I think it makes more sense buying something dedicated for the track. The reason I say that is you're probably going to say something like, "well, I could shave a few seconds off by changing the brake pads...well maybe the rotors too." "I bet if I remove the seats and get some lighter wheels, that would help." Once you start that rabbit hole, it would be cheaper just to get something smaller, lighter, and something you don't mind experimenting with rather than screwing up a perfectly good road car.
Plus, the road debris and rubber on that brand new paint? Ugh.