thanks aka_NSX. just opened my box received today in mail.

the one i bought from eBay, has following 3 wires:

1 - 12V +ve (Red)
2 - Ground (Black)
3 - Light (Yellow)

i suppose these above 3 wires will simply connect to wires in roof-light (need to remove roof light, and replace with this screen as this screen has its own built-in roof or doom lights)

then it has one S-Video cable which basicaly i need to run from middle of roof (where roof or doom light is) to floor. (they way you sugegsted aka_NSX would be the best, but still have to check in my car tonight)

and from that point it has a new cable which has s-video plug and on other side and regular RF video and audio connectors for 2 Video inputs.

still waiting for DVD plyer to get delivered. but seems like its gonna be a busy saturday