Have you got the sunroof? If not, roof mounted DVD player is the way to go, see my install here ;

http://i76.photobucket.com/albums/j2...Picture006.jpg
and
http://i76.photobucket.com/albums/j2...Picture007.jpg

The bonus is that it can be seen by the 3rd row of seats, and because it's roof mounted, no motion sickness. I've got this hard-wired for power so it comes on with the car, and it plugs in to the aux-input for audio. It also works with four sets of IR headphones so if we don't want to play the DVD through the stereo, kids can listen to the film whilst we have music on in the front.

Works great.