I have roadrunner running in my car right now using the lsxvoid skin. I used a 10 inch touchscreen I got from gooddeals18.com i think is the name of the place for ~$200. I built my computer from e-itx.com and newegg.com. It works pretty good but wasn't really that cheap
120gig hd that syncs up to my main computers mp3 folder every time i get home and get within range of my wireless. It works good and so far I am glad I built the computer into the dash. I don't know how much work you are planning to do to your dash but fitting a screen in there can be a real pain since the defroster controls are probably in the way and will have to be moved.