Nice project RaceBear.
Have you got a pic of the airco unit in the car, to where it sits in the car?
I have this one as the TS-screen http://www.cartft.com/catalog/il/601
The car only has a sunroof, and your's has a lot less roof. So you need a sunlightreadable screen. A lower position would be better, but a bit off a downside you see less of the road.
You use linux, i don't, should be faster than xp.
For the skin my best advice is to place the buttons with the same function on the same place on eatch page, and don't make the to small.
Are you also gone use the cpc for the tuning?
ps Almost forgot, don't use this: http://www.cartft.com/catalog/il/937 there always stays a bit of air under it and when you use a light background like internetexplorer they sort of light up and thats irr..