cigarette lighter wire(It turns on and off with the car. You'll have to take the center counsel apart). I then ran the wire around the passenger floor area, up the passenger side pillar, and over to the rear view mirror. The wire is hidden the entire length. My radar detector sits above the rear-view mirror on the passanger side. It's not too noticeable if your outside the car. The detector comes with an adapter so you can hardwire it. I'm sure there's an easier way, but I'm happy with the set-up.