Seriously, a laptop/table pc? ick. Look

That's a 10.4" Touchscreen LCD in a 1996 (IIRC) Eclipse. Entirely Built and setup for ~$700USD (not CDN) That's BADASS, a tablet or a laptop is just ghetto for a car. And I'm SURE you could build in a nice little sliding cover for that, just like a rolltop desk, couldn't be too hard.
More info :
here
