I found the easiest way to install a rear backup camera in a Subaru BRZ cheap and w/o having to drill any holes is:
1) Buy the following camera (you do not need one with lights for nighttime):
http://www.happyshoppinglife.com/car...on-p-2307.html
2) Buy the following wiring harness:
http://www.autoharnesshouse.com/19867.html
3) Learn how to remove the radio/navigation unit:
4) Remove the factory license plate light cover.
5) Install the new license plate light cover w/ the camera.
6) Remove the radio/navigation unit and remove the 10 and 16 pin connectors. Plug in the new harness 10 and 16 pin connectors in to the back of the unit. Plug the original 10 pin connector into the new harness. Note: the original 16 pin connector is no longer needed and can just rest inside the cavity.
7) Plug the camera RCA jack in to the harness and connect the red wire from the video cable to the 12v connector on the harness.
8) Run the cable to the rear of the car and connect the video RCA cable to the camera and the red 12v wire to the camera. Connect the ground wire to the nearest ground. (You can always run the cable through the center of the car first to test.)
9) Turn the car on and put the car in reverse, you should see the rearview camera image on the screen.
10) Adjust the grid lines on the navigation unit:
http://ae64.com/Rear-camera-install-16p-FT.htm
Total cost was under $50.00 and 30 to 60 minutes of your time.
Good luck!