well, i've had a few monitors in my car. I run a carputer set-up and I orignally used a 7" motorized screen which was nice but blocked the climate controls. I then moved up to a 8" widescreen monitor which fits flush inside the double din slot but then you don't have a stereo. If you get creative, you can create your own dash like I did. Right now i'm running a 9" touchscreen with a deck installed below the screen and i'm going to relocate the climate controls overhead buy the map light. Here are some pics of the monitors I used:
This is the 8" monitor I had...
http://4tecko.com/images/Prelude/com...0Converted.jpg
this is my new and current dash piece which is now installed and wrapped in a blue velvet material. I don't have pics of the final product yet.
http://4tecko.com/images/Prelude/dash/004.jpg
I hope that gives you some ideas for monitors though.