[surfmike]

Creative ideas. However, discoverability is poor. Can you imagine getting a rental car or borrowing a friend's car and getting this to work?

Also, this uses a whole iPad screen to control 8 settings-- eight knobs would take less space and maintain the benefits of a physical interface.

Personally I think commonly-used controls like volume, temperature, fan speed, and some music controls should have physical dials. You can then find them by feel, they're reliable and modeless, and they're much easier to understand. Then, leave the touch screen for navigation and more advanced features.