Although cops do thier "job", there are a lot of them are corrupt! My manager at my previous job was a DC cop. The stories he could tell you will amaze you. From framing "black" guys to beating them to a pulp. I think, and a lot of cops might say, citing a vehicle modification is a judgment call. But, for some reason, I've never seen or heard of a Harley Davidson with thundering exhaust pulled over for noise pollution or whatever. Those things are 100X louder and annoying than any exhaust IMO. Makes you wonder sometimes.