check this site out.
about installing computers into cars – much more interesting / powerful / cheaper / more functions etc than installing stand alone car shite (eg dvd plaer, headunit etc)
some people use voice recognition etc and can power their windows, aircon, gps, dvd, divx rips, not to mention at least 80gig of mp3s and shite! use wireless to communicate to home desktop, internet on the fly? awesome.
http://www.mini-itx.com/projects/bmwpc/?page=1
for more info checkout
http://www.mp3car.com
i’m saving up now!