I recently had a local mechanic switch a Sony receiver and a Sony 10 CD changer from a Buick Century 1999 to a Buick Regal 2000. The changer doesn't work at all now, and the player is acting possessed (opening closing, graphics display now gone, etc) I had another place look at the car and he said everything was wired properly. A few minutes before the car started doing odd things (all lights turning on, off, and car wouldn't start) There were some minor issues before with the car with traction light coming on then off a couple of times. The installer used the wiring harness, antenna adapter, etc from the other Century for the Regal, which should be the same. Could the car have ruined the stereo, or has the mechanic ruined the car+stereo?