Key for wheel lock nuts missing!!! Need help!

I just realized that the key for the factory GLX wheel lock nuts mysteriously disappeared from inside my car. I called the dealership to see if they could order another key. They said they need a code that's either printed inside my owner's manual or one that's stamped on the wheel nuts (took them a week to figure that one out) -- I couldn't find anything in the owner's manual and I couldn't see anything stamped on the lock nuts.

I'll be taking it to the dealership first thing in the morning so that they could find out the code to order it. Does anyone know another way of finding the key code?
Thanks!