I used to be a cop in PA, by law, your tires are not allowed to stick out AT ALL beyond your fenders! You will, however, see plenty of vehicles on the road in violation of this. I talked to a guy at a shop one time who said that a lot of inspection places will pass the vehicle as long as the tires are not sticking out too much (like and inch or so). Regardless, if you get a very bored or maniacal cop behind you, or if its 2AM on a weekend and they're hunting for DUIs, watch out, it would be a legal traffic stop.