Use my Iphone 3g as movie player

I wonder if anybody can help.
Already have in my car a Active Iphone holder, which can charge the iphone but also allows me to attached everything to my carstereo,so i can listen to my music.

http://www.mytrendyphone.com/images/...20CMIC-102.jpg

Only thing that this holder does not have is a TV-out.

And that is somthing I really would like to have in the car.That way the kids can watch a movie when we are on the road.

Idea is to mod this active charger , and solder a tv-out cable so I can connect it to two 9" headrest LCD.

Have already been trying to find out the pinout of the iphone connector, and it looks like I need to use pin 8:

http://sree.cc/wp-content/uploads/20...Phone-pins.jpg

My question is:

If I buy next cable, and took it appart and solder Yellow cable to pin 8 of my existing connector on the car holder/charger.
Will TV-out be possible??

http://i2.expansys.com/img/b/179529/...pod-iphone.jpg

Or will it not work at all??

Buy the Apple cable. It includes a USB port and audio/video outs that will work for sure. There's a chip in the cable and TV output without the Apple cable is iffy.

but-- if you are focused on doing this yourself, you will need to look at more pins.

pins 1 + 8 are required for a composite video signal.
pins 15 + 21 are "device connected" pins-- you need a certain size resistor across these to trigger the iphone to allow the tv-out.

also, all of the apple connectors i have looked at on pre-made devices have never had all the pins. just the ones needed for the pre-made device to operate. so that means you would need to purchase a fully-pinned connector, and hack everything together yourself..