Man I got pulled over yesterday by a state trooper for modified exhaust. In Mass we can't do anything to the exhaust that increases the "sound" over stock. He quoted me the law wrong, saying that it's illegal to make any modifications to the exhaust. I explained to him that I had my exhaust professionally installed by a muffler shop and that's what they are in business to do. I said, "so what you're telling me is that if I have a new muffler installed on my wifes mini van that does not have the same sound characteristics as the stock exhaust, then it's illegal?" BS. The law in Mass is so subjective. There is no decibel spec to go by. If the cop thinks it's louder than stock, then it's loud. He let me go, but gave me a ticket for my front plate not being on. He obviously knew he didn't know the exact law becuase he didn't ticket me for it. Mass cops almost never let you off without a ticket.