oh nvm, I had the thoguht u wanted to use ur laptop with a LCD on the car (carputer style) U can do what was suggest ealier, using a headphone jack to RCA, than wiring that to the AUX input that most headunits have on the back. Or u can pickup head units that have the Aux input that has the 3.5mm (headphone port) and get a stright 3.5mm cable from ur laptop to ur Hu. Just go look for a HU and post the link and I'll see if it should work for what u need