After a year, I finally got around to pulling the hubcap off the spare, and found that I do in fact have the lock. The plate was in a box of parts I got with Patch, but the lock part was on the nut with the spare. The bad news is that none of the keys I got with the truck will open the lock. I have lock picks, but before I spend a bunch of time trying to pick it, does anybody know which direction the lock turns to unlock? It seems to be clockwise, but everything else on the truck unlocks counterclockwise.