Hey Tom,
I sorry for the late reply. As far as fitment goes these wheels fit awesome. These wheels are the only aftermarket wheels I know that are this wide and designed specifically for the S197 Mustangs. It's a tough wheel to beat for the price and quality. Personally I'm not a huge fan of aftermarket knock-offs of existing OEM wheels. I like to see something different. I have no fitment issues other than the fact that the inner wheel lip will touch a bump on the inside fender well when the car is lifted off the ground with a jack or lift. During any driving conditions I've had no issues. Remember, that's an 11" wide wheel out back which is about 3" wider than a factory GT wheel! It would be nice if some tire manufacturers would offer either a 305/35 20 or even a 315/30 20 tire size for out back.