There is a writeup on this in the FAQs. It outlines how to test your setup using an ATX power supply on your workbench.
Im using an Acer Aspire Revo with a carnetix P1900 and have it wire to the computer but was wondering if there is a way to test the power before doing all the wiring in the car. Would like to make sure I get it right.
On another note I have one of these but it doesnt work as the only monitor so was wondering if there is a way to convert it to a vga input and use it. If not then suggestions on a non touchscreen 6.5-7 inch monitor for relatively cheap to use. Thanks