The screen is a bit on the crappy side of things. It can be operated independently of the navigation unit in the trunk of the car, but it requires a communication with microcontroller.
The communication protocol is uni-directional (screen is always receiver) and serial. It uses (or is usable with) 5V logic.
1 - Red channel for RGB 2 - Green channel for RGB 3 - unknown, NC 4 - serial data 5 - remote control sensor (I believe it's output from IR receiver mounted in screen) 6 - Blue channel for RGB 7 - video ground (chassis ground too, I believe) 8 - Sync channel for RGB 9 - unknown, NC 10 - composite video input (75Ohm terminated).
Overview of the protocol: https://github.com/festlv/carpc/blob/master/avr-firmware/src/rti/rti.h
Implementation for AVR: https://github.com/festlv/carpc/blob/master/avr-firmware/src/rti/rti.c
For more information on protocol, see: http://translate.google.com/translate?depth=1&hl=en&prev=/search%3Fq%3Dwww.youtube.com/watch%253Fv%253DmQNQ2uDwl6I%26hl%3Den%26client%3Dubuntu%26channel%3Dcs%26biw%3D1916%26bih%3D971%26prmd%3Dimvns&rurl=translate.google.lv&sl=sv&twu=1&u=http://www.svxc.se/phpBB2/viewtopic.php%3Ft%3D18273%26postdays%3D0%26postorder%3Dasc%26start%3D180%26sid%3Dc0b78a6ad506d1f0017904843254b43e#endif