Well got the PC in the truck and running. Still not 100% complete, I'm working on permanently mounting the LCD now (it's currently residing in the glove box). Here's what the system is:

Epia V8000 ITX MoBo
Lilliput 7" touchscreen LCD
80GB 7200RPM HDD
DVD ROM drive
300W RMS Power Inverter (couldn't afford the DC-DC route)
Delorme GPS software w/ Earthmate USB GPS receiver
Mediacar w/ approximately 20GB worth of MP3s

Due to a lack of space in the truck I ended up building a false floor in the back of the truck to house the Power inverter, P/S, motherboard and Drives. Eventually the DVD ROM drive will go in the dash under the stereo. The LCD is going to be mounted in front of the shifters in a fiberglass panel which I started building today (hopefully it'll look stock when it's done, it's pretty rough right now). I'm using an FM modulator to feed the signal to my old Sony CD player until I can afford to replace the deck with something with Aux inputs. I'll post pics when it's all done. Just glad it's up and running.