There's a bunch of places you could tap into.The easiest and most reversible method would be to get one of those "add-a-circuit" things (such as at
http://www.amazon.com/Littelfu...BGELQ or
http://www.amazon.com/Bussmann...KEXK2 and probably available at chain auto part stores) and use that to tap into the fuse box. You could tap the CIG, WASHER, WIPER, rear wiper, fuses for a switched source, or the INV, PPOINT, DOOR, HORN, DOME, POWER, fuses for unswitched. There may also be empty slots inthe fuse block that are hot.If you just want to cut a wire and tap into it, then the easiest to get to would probably be the power to the radio or the in dash 12V outlet/cig lighter. Check out the various radio wiring threads to see which wire to tap there. There's a lot of power run through a junction box just over the glove compartment, but it's a bit much to access and adequately describe which wire in there you might want to tap. As others have said, it would be fairly straighforward to tap into the 12V in the center console and run a wire under the carpet back up under the dash. Where are you going to mount it?