In the process of buying a 2003 chevy cavalier and it has one of those passtime anti theft devices on it. The stereo says "locked" on the display so I have no way of having any music while driving around! The owners manual is gone, so no help there. The guy at the dealer said he would have to check to see if he can find one. Anyone know what I can do? No code to stereo is gonna mean no deal on car!!!!