I dont think youll be satisfied with the car by any means if you had a 650rwhp camaro and like power. Its a quick car but never "feels" as fast as it really is (the beautiy of it) because of the linear torque and hp curve. Even with a supercharger my car never felt that fast, but yet I was able to beat 650awhp GTR's.
In regards to bolt ons - I was full catless exhaust, intake, tune, pullies and able to pull about 5 cars on a stock M3. The best abng yoru your buck is a primary cat delete and tune. Youll get about 30whp from that.