This lead me in the right direction, and thanks for that. Supposedly the only store that carries them is the warehouse store on Hillsborough a few miles west of the airport, in a shopping center with a Big Lots. I tried to buy them at the store on Hillsborough near 56th and they told me the only store that carried them was the warehouse store. I can't speak for the truth of this statement at other locations, but I can at least verify that the east Hillsborough Autozone doesn't have them, and the warehouse store does... in a $25 box of 52 strips that will last me the next 10 years .

It's worth it, though. Now I've mostly gotten the hang of changing tires (I need to work on not scratching the hell out of my wheels in the process), and I just did a static balance on the front wheel today, so the last two things I had to go to a dealership for (outside warranty work) are taken care of. Ahh, self-sufficiency.