Just finished up the dashboard software for this. I decided to go with winXP with roadrunner dashboard. I did up a skin to use Streets & Trips aswell as the Scantool.net software included in the skin. This allows for both the softwares to be run without their window borders and imbedded inside the dashboard. At some point I will be rewriting software to have some skinnable guages. I plan to do this in python so it will have linux support also since I want to get off of XP as soon as possible.
On that note I would like to convert to linux at some point assuming that I can find some good linux GPS software. Writing my own OBDII software should be pretty easy as most of the current free opensource ones are incomplete and amature.
For now I just need to go into the trunk and shut off the inverter whenever I park.. Guess how it is will hold me over for at least the show in Zion this saturday.
My soft-modded xbox goes in next (custom dashboard 200gb drive). That has a bunch of emulators on it: NES, sNES, Genisis, Neo-Geo, Play-station, MAME, Atari.. soon as I get my 2 wireless controllers. Right now it has 3 el' cheap'o 10gb drives I had laying around from doing people's xbox harddrive upgrades. Future plans are drive upgrades for sure.
After all that I get to try to figure out where I'm going to hide all the equipment in the trunk when I start to plan a stereo upgrade.