you're overlooking the BEST way to use a laptop screen in the car, which is to have it run off of the laptop it belongs to...... you can get an awsome pentium m laptop, athilon xp-m laptop, or even a cheap pentium III with a lot of ram.....(p4 laptops run to hot for in car use) total system costs can be pretty low using this approach as an added benifit....considering the fact that a good tft monitor alone is several hundred +...
one of the biggest drawbacks of using a laptop screen, regardless of whether it is run off a controller or the laptop itself, is the fact that most laptop screens aren't very bright........ this should be high on your "spec.s to consider" list in choosing a laptop screen....there are modifications that can be done to laptop screens for brightness enhancements, but they can be very costly....
HERE is one example of a laptop screen install, laptop & all.......