If this has been posted, I apologize, I haven't been here in ages and I am currently working on a setup using this technology and though it would benefit others, especially those on the low budget.

[media]http://www.youtube.com/watch?v=5s5EvhHy7eQ[/media]

If this ever got big enough, the multitouch feature could be implemented into GUI development for car computer systems (forgot what the common name for these are around here); not sure how, but I'm sure developers could get creative. Either way, this is a great way to turn any laptop screen into a touch screen. The only thing the installer would have to worry about would be mounting and powering everything attached to the computer in the car.