Rather than splash out on a proper in-dash screen, i took my old eee 701 netbook, pulled the shell off around the 7" screen and it fits nice and tightly into the spare din spaces on the dash. I spraypainted the aluminuim black to try and blend it in.
There is a small gap on the left and right of the screen but its hardly noticable and i will be getting some black imitation velvet or something similar and making a plastic border to put around the screen.
The power supply cable had been cut and wired up to the back of the 12v cigarette / power socket so it runs directly off of the car with the eee's battery acting as a ups giving an hour or so of playback without the engine running. When the key is turned on it starts charging just like being plugged into the wall.
To control it, i am using a usb numeric keypad which also has a built in usb hub so i can easily plug in a vodem or usb stick to load on more music. A batch file can be run using the keypad controller to turn on its wifi, connect to the home network, download any new songs off my file server then turn the wifi back off.
The software is called media engine and i have designed a custom subaru skin, windows xp boot screen and i believe it also can integrate with some popular gps mapping software which i have not yet looked into. Media engine can also start winamp visualizations and play avi movie files
This system replaces a standard laptop under the passenger seat that was hooked up to a vga to composite converter, which ran into the stock standard japanese ntsc-only screen that had less than 640x480 of resolution. It got its power supply through an inverter and was very inefficient on battery life without the engine running
Heres some pics and a video for anyone that is interested
http://www.youtube.com/watch?v=2SQsSzQyst8


The white thing next to the can of redbull is the usb keypad
Sorry the camera lens is very speckly on this 5 year old camera
Now i gotta find a new place for my cb radio / cop scanner