Ready for an M3

Hello all of you Bimmer drivers, I am new to the BMW camp, I haev been at the Porsche camp for quite awhile now, I have a 1987 944S that I love to the point of insanity. I autoX it as much as possible and try to drive it like it is meant to be driven.

I recently drive a buddies Dinan modded M3 coupe.....HOLY S*#T!!!

Loved it.

So much i am going to buy a 4dr M3 and go to town on it with modifications etc. I want cold air intake, exhaust, chips, suspension bars etc.

I would appreciate any suggestions all of you might have for me in looking for my first BMW. I have a 15-20K budget, what can I expect for that? I am not going to but a high mile car as I dont want someone elses troubles. there is a 2dr M3 down the road from me with w new engine fromt he factory and a few mods already but I dont want a pre modded car if I can avoid it, although i will not turn a well tuned car down.

Thanks in advance for help. I look forward to poting here alot.