The code should be on your glovebox itself, in the inside or the side of it. If not you need to take the car to the dealership so they can lookup your stereo serial number. I had the same problem..... except my car did not have the code for it.
my mother got her car fixed and now the music is not working.. the screen asks for a code and i have no idea what it is.. i dnt have the book so any assistance would be nice.