I recently pulled a stock stereo from an '05 Matrix XRS to go back to a stock radio in my Matrix. Apparently I need a security/stereo code to make it function. I got the owner's manual while I was there, but the code isn't in there. Can anyone tell me where the code is normally located? I can go back to the junkyard and look for wherever it is if I know, but right now I have a useless radio.