[Arfa]

My wife has just upgrade her laptop, which means we have an old Apple iBook going spare. Kinda toying with the idea of sticking in the car as some sort of video playback device or the like, either dvd's or vids off the hard drive.

First up, it would be best to feed video from the Mac to a screen, either on the roof or in head rests. Why is it almost all in car screens just have composite video inputs? That's got to suck, surely? I see there's an Alpine PKG-2000P which has s-video input, but it costs a bomb at over £700.
From the Mac I can get composite, s-video or VGA output. Also most screens have a res of just 480 lines high? Seems quite low, is that enough good enough for DVD's? Always thought SD PAL was 576 lines high.
I'd almost certainly get an professional to fit the roof screen, how much should I expect to pay (minus cost of screen itself)?

For audio, I've got a Kenwood W7544U HU, which has a line in jack, so straight forward there to wire in. However if kids in back are watching stuff and I want to listen to music, then headphones will be in order. Would it be possible to drive 2 or 4 sets of bluetooth headphones directly from the Mac (it does have bluetooth built in)?

Next problem would be the placement of the laptop. On your lap would be a bit annoying. What's available for mounting a laptop in the car? I can almost envisage some sort of arm, which you swing/swivel it about on to bring it whoever needs to use it.