Does anyone know how I can remove the stereo in my 99 Cadillac Deville and replace it with an aftermarket CD player? Cadillac tells me can't be done. yea right! I've tried a "professional" installer, he is baffled. He tried it once, it worked for about 3 seconds then the alarm started going and it wouldn't stop.
check Metra to see if they, PAC, or a similar company offers a wiring harness that bypasses the security feature when replacing the head unit. Honda has a similar issue on newer cars where their haed unit is somehow wired into the keyless entry and power locks etc. If you just swap head units, it screws with the factory door locks and such. hate that crap.
go to best buy they ahve a relocating wire harness for your car it buts your stock deck in your trunk. they cost $60.00 but it is well worth it so you dont go through all the trouble like i did with american, they're install guys don't know crap!!!!!!