i've done the carputer twice before. i hated it. it had a cool factor only at night due to lcd lighting constraints using a touchscreen. and another huge factor was loading time. i got it down to about 15-20 secs cold start and i still wanted to drive my car into oncoming traffic from irritation. you should fill in/clean up the area around the screen and it will look ok!
heres what mine looked like at night:
