I bought this flip-down screen from autotoys.com for $306 ( now $279 ). We are using a portable DVD, the Panasonic LA-85, as the video source. For audio, we are using a cassette adapter plugged into the audio out jack of the portable DVD player. This is the cheapest way to go for us. If we find it inadequate down the road, I can always buy this Pioneer 6 disc DVD/CD changer or this Farenheit 5 disc DVD/CD changer, and add a FM modulator. We should be ok for those occasional long trips, since the kids watch more than enough TV as is .
My installation took about three hours, going at somewhat slow rate while also entertaining the kids. Here's a summary of what I did. I also have both the service and electrical manuals, which I found to be extremely helpful in locating the panel clips and wiring.
1. Remove rear map light
2. Pull out B-pillar panels on passenger side
3. Mark mounting location of monitor, drill small holes for the plate through roof liner
4. Run the cable from B-pillar to monitor location
5. Mount monitor on roof liner using bolts, washer and nuts
6. Connect lights on monitor casing to interior lights (from rear map light)
7. Remove front passenger door sill trim
8. Run cable to front passenger fuse/relay box
9. Connect power to accessories +12v line
10. Run video source cable to front console, just under ashtray
11. Put everything back