I'm sorry i still don't understand, let me try to clarify my position.
I have a dell 600m as my carputer that connects through vga to my xenarc 7000tsv. I'm trying to get that same video feed into a headrest monitor. However, the headrest monitor accepts only rca video input, and thus my dilemna.
All you need is a cord that has the 4 pin s-video on one end, and the rca on the other. I picked one up from what used to be radio shack up here canada. then you just set it in the displays section to clone the desktop from your primary monitor.
Keep in mind that if you do more than 2 monitors on the same, you will most likely need a video amplifier, you can get one from www.MP3playerstore.com
Here a pic of my set up to give you an idea.