www.mp3car.com 1000's of people have installed computers into cars, and they will tell you EXACTLY what you have to do. Most people use mini-itx computers www.mini-itx.com, they are small and low-powered. They have enough juice to power a carputer, but they wont play games or anything, but if you want to watch dvd's/divx/use gps/play mp3's then its powerful enough, and pretty cheap.