I have somewhat the same question. I have an extra IBM 390X Laptop laying around and want to use that as my temporary carputer until I get enough money to build a normal carputer. I bought the Xenarc 700IDT as a screen.
But how do I get it to turn on if it is in my trunk? I heard about wake on ring and shorting out wires. Any step by step tutorials or an easy solution for a noob? I already figured out how to make it go in to hibernation automatically after my car turns off just need to figure out how to get it to turn back on. Switch, automatically, etc?