[gutnor]

At some point you would probably be better off having physical button. A huge touch screen on which you need to draw weird gestures you had to memorize does not strike me as very user friendly.

That said that is neat implementation and it very elegant but I would like to have that in the living room rather than the car.

A possible evolution I guess would be to have different screen you would flick through that would group 2 or 3 command together with a big visual cue on the background.