This is something that I definitely want to do but just don't have the time at the moment. Gonna have a computer installed in to the car, with a touchscreen in the dash.
Touchscreens, car psu's & voltage regulators etc can be got here
http://www.mp3car.com/store/
There not two expensive.
There's alot of touchscreen based software that will run the system.
Media engine is the one Im thinking about but don't care as long
as it does the usual, mp3, dvd, divx, GPS(not to fussed on this), TV & radio. There's more info & forums here
http://www.digital-car.co.uk/
Screenshot of other completed cars
http://www.mediaengine.org/index.php?screenshots&results=5&start=1&page=1
I found one guy in the uk that his done in his fto but he didn't
integrate his screen into the dash properly
http://www.stuffandting.com/carputer/
When I do eventually get round to it, the installation
and unforeseen problems will be a nightmare but it
will all be worth it!