I've heard of a lot of shops around here (I'm probably only 1/2 hour from you) that do stuff like that. You'll take your car in to get something done, and next thing you know, the same people who put the stuff in take it back out of your driveway/off the street one night. I always give fake addresses whenever I bring my car anywhere unless its someone I trust. If you're gonna go back to that shop and ask around, don't do it yourself though. They'll probably remember you. Have a friend go in there and ask about the b16, and see what they tell him.