Did you have to make the splices right there in the bend of the wiring harness near the hinge?

I have been having an intermittent "Check License Plate light" warning. This means it's getting temporarily open-circuit. My guess is that you've discovered a weak point in the routing of the wiring harness. If the wire lengths were not long enough to allow for the normal opening and closing of the rear hatch they could eventually fail.

Making the splices right there in the bend of the hatch would be difficult to do and also difficult to seal from moisture. Would it be possible for you to provide some photos?