I installed the prothane bushings on my car when I got my SIII's, and they do make quite a difference, especially in the rear. The stock bushings on the rear tension strut are very large (over an inch thick at each end) and contain a significant amount of play, so much in fact that the toe angle on the rear wheels changes under load, toeing the wheels up to 3/8" of an inch (from manny z), which contributes a lot to the snap oversteer problem noted on these cars. I haven't drag raced my car as of yet, but I have noticed less wheel hop since installing the prothane bushings, although that is most likely a combination of the bushings and the co's.