Will this even work if you wire it into the reverse light? Read the section Camera Detect:
http://ae64.com/Rear-camera-16p-operation.htm
It's not difficult to run the camera wire to the HU. See my post here:
http://www.ft86club.com/forums/showp...5&postcount=20
If you purchase a camera that will run on 6V, like a genuine Rydeen, then all you would need is SVXdc's Bypass wire harness.
http://ae64.com/Rear-camera-16-pin.htm You do not need a reverse trigger wire with a BRZ.