I saw this coming . I have had an in dash touchscreen car pc in my 350z since 2005 when I got it. I think the glare is too much for driving, they are defineatly going to need some sort of gloss reducing overlay.
ive been thinking since the iPad was introduced that would be a sweet way to use one... if only I had the finances to make it happen... but the glass screen in a car during the day makes iPad hard to use in reality.