Brad,
I’m running EC-7, et35 18×9.5 all around with 255/35/18 Yokohama AD08 without any rubbing issues. This is stock suspension with minimal camber in front. I think I could fit 265/35 all around, which is what I’ll get for next year.
If you haven’t seen it yet, here is a good thread done by Apex to see different fitments on E46 M3:
http://forum.e46fanatics.com/showthread.php?t=959715