Try wiring it to the ignition loom, if you take the steering column trim there is a plug with a grey clip, that goes to the ign barrel and with a tester you should be able to find a +ve for when the key is in the ignition or ACC position.
On some cars the cigarette lighter stays on for a few secs after the car has been turned off, plus you will need less wiring since you wont need to run wires all the way to the center console.