I think this is a really important point. Sure, an infinitely flexible touchscreen has a nice wow-factor on the showroom floor, but when you're on the highway

I think this is a really important point. Sure, an infinitely flexible touchscreen has a nice wow-factor on the showroom floor, but when you're on the highway screaming along at 65 (because you're a good law-abiding citizen) and you reach down to change the radio station and hit adjust heat instead, and then the map destination, before having to take your eyes off the road to follow your finger to the right spot on the piece of glass - touchscreen not so good. I'd give up some fancy full-color api driven whatever for a nice compliment of ergonometrically designed knobs and buttons any day. As to voice, I think voice-feedback could be a good start. I have a hard-drive based music player in my car with an excellent audio interface. You can reach down, twiddle the knobs and browse through thousands of tracks without taking your eyes off the road at all because it reads the artists, albums, playlists etc to you. Very fine approach to a mobile interface.