I just ordered a set of XXR 521s for my cobra and went with the +12 offset (18x10) for the back and the +22 offset (18x8.5) for the front went with 315/35/18 for the back and 245/45/18 for the front, i have little knowledge of wheel offset but the FR500s i had on my old gt with a Cobra IRS on it, had +25 offset and were 18x10s with 295/35/18 and they were tucked in the wheel well, im happy if the tires stick out 1/2'' but does anyone know how these will most likely turn out?