As far as the location for the rear-view camera lens-- don't forget about the "Dummy Plug" location on the rear tire carrier (located just below the big word ISUZU)!!! This is exactly where the local domestic Japan Version VX had the OEM stock camera lens. On USA export models, it's a Dummy Plug.

The cool thing about the existing Dummy Plug location for mounting the actual camera lens is that it's already at a 45 degree angle. Thus, the camera view shows the back edge (hitch area) of the VX rear bumper and any protruding objects as they enter the camera view when backing up. This would also work great when trying to hook-up to a trailer.

I don't like the License Plate Frame Camera's because they don't look downward at a 45 degree angle and show the edge of the VX rear bumber. Consequently, it's still possible to back into a very low slung object that is just out of camera view (crunch, crunch).