what exhaust should i get i want a stock m3 exhaust. are all cat back for e36 the same size? or do they vary etween 2 and 4 door? does the 3ltr m3 engine have bigger headers than the 2.5? if i would find a full m3 exhaust would the whole thing work or would i need diffrent headers please enlighten me i only owned a beemer for a week [bmwdance]