hello
i have a 2010 A5 2.0
background:
i want to mount a video camera on the front bumper or grill and run the cable from the camera to the control unit inside the cabin (legal protection). the control unit plugs into a usb adapter mounted in the cigarette lighter and will automatically turn on the camera when the car is starter.

so how to run the cable through the firewall? hopefully without having to drill a hole.

 

im honestly not familiar with the newer audis but look under the drivers side near the pedals. Alot of times there are rubber grometts u can remove to run wires.

 

By power wire, I assume that you are talking about an amp or another accessory to that sort. You will have to look up behind your brake pedal toward the corner, there should be a small hole cover with a black 2-way, just push the wire through the 2-way. If you car does not have a hole that you can see, you can drill a small one in that area.