MPG123 will run on a AMD 486dx 100
GPS mapping software runs on a 33 mhz dragonball processor
A/C control, window control, engine control, etc don't require much processing.
Put the OS on a CF card, get a hard drive for mp3 storage, and a USB WLAN adapter and this thing will do everything except movies. And you don't have to worry about heat issues.
as far as the other person complaining about my post, I don't see what the problem is. I found this piece to perfectly suit my need for in-car processing, and I paid a pretty penny for it. I just lost my intrest in the project when I bought a brand new car. Why shouldn't I put this up here for someone with the same idea that I had to buy it off of me for a lot less than I paid for it?