[M3-Mike]

I tapped into the cigarette lighter socket power feed. There is a wire easily accessible once you remove the passenger side center console front lower trim piece which is easy to do. Then just run your wire forward and up under the passenger footwell area and up the A pillar to your camera. Works great and since cigarette lighter stays on for about 10 minutes after car is shut off, it records me walking away and what happens around the car for the next few minutes too.