Eradicator

Has anyone begun work on installing an aftermarket LCD screen? It seems like there is room under the dash where the factory unit would have gone, so it may be possible to create a pivoting unit that closes down into a more concealed position when turned off. I'd love to have a screen up there, but I don't want it sitting on the dash like a friggin' depth finder when I'm parked downtown.

I'm interested in getting a retractable screen up there and then using a small computer to power it. With a PC, I'd be able to have a navigation program, mp3's, movies, and maybe even add some car diagnostic monitors.

So for starting off, I think the main questions would be
- How much space is there under the dash?
- Is there a wiring harness (for power, and more?) already available, or will it require a tap into some other power line?
- Is it possible to use the stereo's 2nd source input for the computer's audio output?
- Can the stereo be modified to output 5.1 audio?