Props to you, good work! It's pretty much what I'm planning to do for about 2 years now...... except that I'm going to build my own graphical user interface, (try to) connect the PC to an e-manage and my wideband O2 controller, with a custom logging display optimized for the small screen (without all the big buttons and title bar and stuff), custom mp3 player and so on...
I also have an Epia M10000 lying around for a few months, just haven't had the time to install it yet... so I'm currently using it as a DVD player in my living room.
Once the PC is in the car, I'm planning on connecting it to my cell phone via bluetooth, so I can do some party tricks like open and close the windows from the outside, start and rev the engine, view engine parameters on the cell phone display etc.etc.
Free wifi hotspots rock! I wish we had something like that here