Can I "Invert" my video image?

I would like to use a new iBook or Powerbook as an "in car" game station and/or DVD player for the kids. It would be great if I could invert the video image so I can mount the laptop upside down on my Van roof liner. I have mounted an older Bronze Keyboard Powerbook in the upright position which makes for a bulky bracket and you can't really flip the screen or laptop out of the way. The screen on my old powerbook puts any in car entertainment system to shame and I am sure a newer iBook or Powerbook would be even better. With a Deluo Bluetooth GPS tracking unit and Route 66 software, the Powerbook becomes a useful multi-use tool on trips. Get to the hotel, remove it from the car and surf the net from the hotel room.