I am rubbing in the back with 10mm spacers on stock sized 265 tires. My car is nowhere near as low as the OP's car but rubs when cornering on track.
I have about 1/2 inch fender gap between the rear wheel and fender. Does not rub under normal driving. Running 2 degrees rear negative camber.
Here is my original post about it:
http://www.m3post.com/forums/showpos...&postcount=372