[The HACK]

Problem is not the fenders. Problem is the trailing arm. Even at 18"x9.5" et 26 on 275/35/18s, on hard corner the tires (R-Comps) deflect enough to touch the trailing arm. Anything wider than that foot-print (typical of Nitto, the 275s probably run about 10mm wider than equivalent street tires) with offset one way or another will rub either on the trailing arm, or fender if no additional camber is added. So for example, a 285/XX/?? tire will likely either rub the trailing arm if the wheel is wider than 10" with et in the 25 or more range, or it will rub the fender if et is in the 20 or less range. And you can forget running anything like an extreme summer or R-Comps, since those tend to run wider than typical street tires. 285 on 10" with 25mm may clear with the rear camber maxed out, but will still likely rub the trailing arm when suspension is loaded at high G for extended time (high speed sweepers).