Check the owners manual for a number that was written in ink pen, usually near the back. If not, check the underside of the fuse cover under the hood.. Dealers used to put it there. If you have the manual, it is almost always in there, or on a business card inside.
If that fails, hit up the dealer, they can look it up. Don't take "no" or "we can't" for an answer. They most certainly can.