Interesting - i just found an article at
Automotive » Blog Archive » Audi Advocates Touchpad, Voice over Touchscreen Interfacing where Audi advocates touch pad like on a laptop over a touchscreen - they claim that touchscreen distract the driver more, and the car veers off the road when a person is using the screen... touchpad is even better than idrive...
That shifts my paradigm - I am not inclined as much towards the touchscreen anymore... but this is not a final verdict!!!