ive put computer into many things such as model cars, the mini-moto shown in the link above and anything that takes my fancy... there are many people doing it... below is a link to a focus rc car which has been converted to a PC... I never did this system but it shows you the idea, i will try to get pics of my friends cosworth that I did. Anyway a replica of your own car looks better on the desk than a normal pc case

http://mini-itx.com/projects/htpc/

The pc in the car thing is not new as shown in the Links below, the very same motherboards that are used for the models are also suitable for car installation, im currently doing one for my Turbo Cabriolet but im also running the ECU through it so that you have to enter a password on the touch screen before the ECU will work (added car security) and a few other trick things

http://mini-itx.com/projects/bmwpc/?p
http://www.mp3car.com/