wants to squeeze on a wheel that's obviously of the wrong measurement specifications to properly fit the car doesn't make it right. A properly flush fitment can be attained without cutting and rolling the fenders. If you want a really aggressive fit that requires those modifications, well okay I suppose, but I wouldn't call that a correct fitment for the car.
My favorite site for getting an idea of width/offset fitment is Will They Fit.com They give a great graphical image comparing different wheel/tire sizes. Plug in one combination with a fitment you know, and see how the size combination you're thinking of compares.
