New "modified exhaust" law revokes registration?!?

[bottledbird68]

Ok, so we got stopped last night after work by one of Massachusetts finest. We were getting gas in the wrx and he pulled in and sat back in the lot waiting for us to leave.
I started the car, pulled away from the pump and he immediately flipped the blues on and pulled me over in the parking lot.
So, he walks up to the car and asks what's wrong with my exhaust. I calmly replied that it was a 50 state legal replacement exhaust (I know technically according to mass it's supposed to be factory, that's not the debate here).
He tells me no way, it's too loud and not legal, takes my license and registration and goes back to his car. Comes back 10 minutes later with a warning for "modified exhaust".
Now here's the good part. He then tells me that it needs to be returned to stock. As of may 1st mass law is changing. "Massachusetts is getting serious about people modifying their cars. As of may 1st there will be no modified exhaust, altered height, or any other such modifications tolerated. If I see this car again after may 1st and it isn't stock I will have the power to revoke your registration on the spot and have your car towed. And, you won't be allowed to have it back until it is returned to stock."
Now that sounds like a load of horse shit to me and I've been searching online for any info and can't find anything saying that. But, knowing mass it wouldn't surprise me and I don't want to find out it's true come may by having my car towed.
Anyone know what's up here? Need to know cause if it's true I figure I have a month to move to New Hampshire lol. Cause I'm not about to return every vehicle I own to stock or buy another one to drive. Or does anyone in nh want a roomate in their mailbox for registry's sake lol?
You want to ticket me, fine. But to have the power to basically impound my car is freakin rediculous.