Do you mean to say that your "Car Radio" is also a DVD player, and has a RCA video output (usually yellow)? If the RCA connectors are only red and white, they're audio only, so there wouldn't be any video signal to output to a video screen from those.
Connecting an old screen to a DVD output sounds like a fun and useful car project. I'm sure there's someone on this forum who can give you a hand with that. Why not consider posting your images by attaching them to your messages here, so people don't have to link to download them?
If your laptop had a DVD player and the associated video hardware, and it's all still intact, it makes sense to try to recycle as much of that as possible, too. Then it would be just a matter of connecting your car's DVD output with the laptop's monitor hardware, effectively swapping your car DVD player with the laptop DVD player.