Nice.
Too bad you can't tap into the surround sound on the truck for it. Oh well, we can't have it all I guess.
Some other tricks I was thinking...
1. Get two xboxs, plug one into each DVD headrest and then: a- play over xbox live against each other and those on the net, b- play against each other over the local wireless lan, c- if your going for the most boring solution, run a 6" ethernet cable between them and play against each other over the wired lan.
2. Rockband in the car? Drummer in the third row, guitars in the center, mic in the front passenger?
3. scene it DVD with the "buzzers" for in car trivia game between all of those in the back.
4. What if you used the xbox as the DVD player for the car? Then you could use the remote control to control it. Better for those who complain about not being able to control the DVD headrests or the xbox from the front seat, put some leap frog IR repeaters in the truck (transmitter in front, receiver/sender in the back corner ceiling somewhere" and then you can use the remote in the front).
....how can we utilize a kinect in the Ex I wonder?....