Hi: Getting conflicting info from car radio installers about this so asking here. If I take out the factory single CD and AM FM in dash unit on this 08 LS to repair the CD drive, will it work OK on refit or will it ask for a code? I just bought this car and someone had the foresight to write down the door code in the owner manual but nothing else anywhere about this can be found. There is no keypad to put any numbers in come to think of it so is there a secret sequence of button pushing or ?? Thank you. --Tom in Tucson