here's my guess, sounds strange to me BUT you put on tires with a larger than stock rolling radius so if the rear is somewhat low to begin with then you may be rubbing. To see what you should have go to preludecrazy.com and check tire diameters ( I think you need 225 40 17's). You maybe rubbing on the inside of the rear not the outside. This is just a guess cause I have no idea what kind of clearance you have. It still sounds strange though.