Brian I am a little late to the party here. On my E30 M3 I am running 225/45-16s on 16x8 BBS RS rims. I have no rubbing issues whats so ever. Now I realize the M3 has boy racer fender flares. BUT those fenders still have lips on the inside. Taking this into consideration, they don't really stick out further than the small fenders on the regular E30. It is really just more of the fender that sticks out. When I had 205/55-15s on my M3 the space between the tire and the fender was about the same as my 318i which also has 205/55-15s. Here is a few photos of my M3s fenders with the stock 15 wheel w/ 205/55 and then the 16x8s with 225/45s. I don't know if this really any help b/c I know the M3 is different. But I thought I would share.