um.... i dont think you can make the xbox dvdrom drive work far away from the motherboard, because of the uncommon wires that connect the two.
but to make it turn on and off, wire an inverter off of a relay, and there's a thing called a doorbell mod that uses a wireless doorbell trigger to turn the Xbox on.
or you can just buy my modified Xbox and store your games on the harddrive, so you could put the xbox in the trunk, buy a wireless controller and be set to go. you'll never need to access the dvd drive. it also plays divx movies and such
