Yes Sharon you will need to remove the radio to see the serial number. You can either buy the "keys" to remove the radio from the dash or you can simply make your own keys using a wire coathanger. Just cut the coathanger into two 9" lengths (approx) and bend them to form a "U" shape that will fit into the holes on each side of the radio. Push them into the holes (not TOO far) and gently wiggle the radio out of the dash.
Post the serial number and somebody will reply with the code. (unless it's a "V" code which can only be done by a de-coding service or the main dealers. They cost money) Good luck.
Bigh
February 2010