Tesla cup holder water bottle sleeve

I recently got a 2015 Tesla Model S. I always keep bottles of water in my car, and the 500mL bottles I prefer tilt in the Tesla's cup holder. While the concept is trivial (it's a cylinder with a gap), it did take some consideration to make it work well. More detail can be found [on my blog](https://risley.net/?p=595).

While I made these specifically for the Tesla, they would probably work for any cupholder with about a 79mm diameter opening at the top and 66mm or so depth.