It would sure be nice if you could measure the offset and backspace on the rear wheel.
That would help immensely.
I don't plan on larger than 285 front. I just hurts to think about the PCS wear/cost.
TC still does not have a good E92 M3 system yet. I have a very well set up 02 MCoupe. I, unfortunately know very well about the slippery slope first hand. In fact that is my biggest frustration, the MCoupe will eat this car for lunch, and give you change.