Ct has a "Subjective" law like that, with no exception for antiques. I was ticketed for loud pipes a few years ago in my Corvette. It's a 74, so it has no cats. I was running stock manifolds at the time (now headers), into a true dual 2.5" Walker chamber system, the same system as the 63-67 Vettes had as an option, but these chambers aren't as long and are mounted under the car. This exhaust quite subdued at idle and taking it easy around town, but is very loud when under hard acceleration. Loud like NASCAR, & that's no joke.
So, I take my car and the ticket to an (unnamed) national muffler shop where they are an authorized state inspection facility, and have them inspect it. Manager takes the keys, starts it and revs it up. Then he idles it in and up on the lift it goes. Every mechanic in the place comes over. Manager says: "Looks to me like this is a dual system with no leaks, (taps on the chambers) these look like some sort of sound supressing device, probably containing some sort of sound deadening material, mufflers. Looks ok to me." I ask if he thinks it's too loud, he says: "I don't think it is, any of you guys think so?" One by one all the techs say "Nope.". I ask if there's a decible rating as a standard, he says "No, just excessively loud". "If this were my Vette, I'd want it to sound just like this". he says. He didn't have a problem negating that ticket at all, and I sent it in like that, paying no fine.
So "subjective" goes both ways. Thing is, it would be very costly to require all the PD's to carry decible meters around and start testing exhausts, so they let it go as a judgement call. This is where SEMA knows they can stop them, bacause it will be defeated if standards requiring equipment are mandated. Voters hate taxes more than the noise, and will still think it's an effective law without standards. For most, it will cause guys to change their exhaust or pay the fine. It's really the best way to oppose it, an that alone might cause it to fail in the legislature.
I carry my inspection report from the muffler shop in my car all the time, just in case one of these yahoo cops wants to get subjective about it again. If you insist on standards, you're all done. That'll make it so that there's a comparison, the allowed level will be so tight that you wo't be able to change a downpipe without going over, and the system will cost so much that the fines will be just enormous.
If this is the way they want to write the law (without level standards), let 'em! It's really in the car guy's best interest, and makes the bill harder to enforce. All you need is someone authorized as an inspector as subjective as the cop who writes you to completely negate the ticket. With standards, you'll need a lawyer to get you out of the fine.
Sorry for the long post, no short way to tell that one.
