I'm sure it is do-able now, but not to the level of accuracy demonstrated on the video. They do say on their website that they think it is tehnically possible as well.

Ideally you would want the top of the car to be a touch sensistive LCD like my Pocket PC screen. That would make it extremely expensive of course.

You could get the same functionality out of a cleanable film of plastic that was touch sensitive, like the suggest in the video, but it wouldn't be as neat as an LCD.

Using a Pocket PC strapped to the top of a radio controlled car body would be the easiest way to prototype this, though the 600Mhz Xscale in my Dell might be a bit overkill for the final product