I called the dealership this morning. Note that they have never called me back when they said they would (they claimed to have called once, but didn't leave a message).

The dealership says they have no extra tires/wheels around, and no recollection of the event.

While I'm one to be a little charitable, the lack of courtesy even in a callback, leads me to think there's a mechanic that has 4 tires and a set of "non-matching" rims. I'm going to try junkyards first and see if I get lucky.

In addition, if it was a very meticulous thief who likes to clean up and by chance I left my car unlocked so he could get to the lowering mechanism without damaging the rear door/bumper, and he brought his own tools to lower the spare (I checked, mine are still there), he also didn't want to steal any of the change I leave in my cupholder or ashtray. A very honest thief.

In terms of probability, I'm about 99% dealership vs 1% thief. I just wish I had noticed sooner. I never thought to do a full walkaround after a dealership worked on my car.

For what it's worth, It's Chapman Chevy-Isuzu in Tempe, AZ.
- I think the guys in the back took the tire
- I know the service guy up front, while very personable, was not reliable or courteous enough to return calls, or to call back after I did make contact with him.
- I'm 0 for 2 for dealerships in Southern AZ, and don't want to have to drive >2 hours up to north Phoenix or New Mexico. Luckily, with the lack of real Isuzu options, I can say unless things drastically change, my next vehicle will definitely not be an Isuzu. Not because of the company, because of the dealerships. And remember I'm the guy that flew from Dallas (when I lived there) to Tucson to pick up a Rodeo.