nissan 2006 sentra ignition wiring

Hi, my friend (a CS major) and I (an EE major) are planning on wiring his car (type named in subject) to be turned on remotely. Since we're nerds, we'd like to build the device ourselves and install it. Since I do not wish to destroy his car though, I'd like to know how the wiring is set up. If anyone could help with that, that'd be great. The device itself should be relatively simple, just need to know what wires do what in his car.

Don't; you are inviting all sorts of problems especially safety and a good chance of destroying the car. Look at the relay section special applications, read the warnings there and then proceed AT YOUR OWN RISK.