joe 
2007 BMW Z4 M Coupe 2dr Coupe (3.2L 6cyl 6M)
Know what you are getting into
 I sold my 06 330i with the knowledge that the M coupe I was about to purchase was very far removed from the 330i in both comfort and performance.  The car is a rocket, but you feel every bump on the road. Also, the "premium" sound system in the M  is sub-standard at best.  Again, know what you are getting into before you buy. If you are willing to sacrafice comfort for performance, then this is the car for you. It was for me. 