The code is to stop theft of radios so do you expect it to be simple to
find. A card comes with the car when purchased with the code on it. Have him
check all his documentation that came with the car if purchased new. The
dealer can get the code with the radio serial number but should never give
it out without first verifying the ownership of the radio and vehicle
otherwise any thief could just call them and get the code. As for the code
saver, yes it will work by keeping power in the system with cavots. If you
accidentally touch the battery + cable to any ground while changing the
battery you could create major damage to your electrical system. So if using
one make sure you insulate the + battery cable when removed from the
battery.....