JohnBoy, John Coffey is right in saying from the cat back, the smog laws really don't matter. What does matter is your local noise ordinance, whatever it is. Usually, unless a car is obnoxiously loud, the police will leave it alone. Even where I live, there are restrictions about loud car stereo music because the public has become very annoyed at the current trend, but I've rarely seen the cops ticket for it.
David