The e46 could and would be a great car BUT consider the following: It will require MOTEC or something similar to make any hp and due to double VANOS you will need atleast a M600 or better unit so expect to have north of $6000 in the unit, wiring and tuning alone. Cam profiles on this car are a little mild so peak hp will not reach M50 e36 2.5 levels and rear diffs for this car ( racing lsd type ) are very expensive. I explored this car and even with the ability to do alot of the prep myself I still figured $50k to build..... Then what if the car kick ass and takes names ????????/