[highwayblaze]

As far as USA goes I don't think cops care as much unless you're in really small town where the police have nothing else to do. Then they'll pull you over even if you fart.
It maybe be illegal to have aftermarket pipes but I doubt they care as much unless its crazy loud. I've seen a couple of zx-10r' s which had stock pipes that did not have a muffler and the remaining was given a slant cut to look like moto gp. LOUDD!!!