I disagree...doing this at a cop is always cool too!!Rule #4
Rev up! The sound of your pipe echoing off the other cars as you pass them will probably only be heard by the cars you just passed, but Who Cares! You look cool and you at least sound good to yourself and any of your other squid friends splitting behind you.
Exception to Rule #4
Unless you don't want to be noticed.
Unless you're passing a cop car.