Take this with a grain of salt... but any law that is 'clearly' not enforced becomes null and void.
Any lawyer worth a piss can get any ticket issued under these laws tossed. It is comon knowedge that there are thousands of cars on the road violating these laws and not being ticketed (being completely ignored), and most any Judge would agree.
I have seen a illegal window tint ticket throw just on this argument alone. A friends car that had limo tint on all the rear and all the side windows. The agument was, it is comon knowedge that the law is regularly violated and not enforced, as such it would be unjust and makes the law un-enforcible. The Judge agreed and tossed it out. The same would go for exhuast I'm sure, as anyone would agee they see/hear hundreds of fart tip muflers every day... hard to call that an enforced law. Mind one thing though, a "new" law changes the whole thing. If a new law is enacted and enforced, then your screwed.
This is the case with cell phone use in cars, there are laws making it illegle to drive a car with anything in your hand that interfears with the operation of the vehicle, also for listening to a "hand held" radio, walkie-talkie, cb-radio, or other type listening device. But, it has never been enforced and as such is not enforcible. A new law would be required to make it enforcible, something that is on the horizon.
