Looking for spare positive and negative wire

[Australian 86]

Hey guys, im just wiring up a remote entry system into my 3G and I'm looking for spare positive and negative wire
to hook it up to. Anyone know where i should be looking?

[iruletheworld]

Not sure about the postive, but for the negative all you need is a bolt into the bare metal frame of the car. The Frame is running negative all you have to do is hook it up. As for postive, I would find something that has a constant 12v. Have you ever done a stereo install?