IMO, in order for a cop to be allowed to fine you, he should have some numerical value to support his claims such as a decibel meter for exhaust, light emittor/receiver for tinted windows or video camera for a rolling stop. Anything short of that leaves a large margin for interpretation errors. I tried to strike up a conversation with the police man as he was fining me for the mufflers, and all he could say was "those aren't stock", like a broken record! He didn't even ask me to start the car or revv the engine...