You can make a skin with one huge *** button on it, nothing else.
Hehehe... the BMW I-Drive way, right?
I'd like to take this for a spin, but the Mappoint requirement puts it way out of reach. There are a lot of other alternatives for navigation out there, and the front-ends that offer a more modular design seem to be more easy to try out -- you can try Frodo with Destinator or MediaCar with iGuidance, for example, and see which approach you like better.
With AutoTouch you're not given a choice... spend $300 on Mappoint (or steal it, but that's another discussion altogether) or don't even bother. Not much people can do about that... and quite frankly, out of all the options for navigation software out there, why did this have to use the absolutely most expensive one?