Nissan Patrol 4x4 (Africa)

Trying to wire up a pair of fog lights and a work light, all on a separate circuit. I was hoping that the door catch can act as a ground, as the bolt threads through the body, but no luck.

Any ideas for a decent ground at the rear of the GU patrol All 3 lights are mounted to the roof rack, and will be relayed etc etc.

There should be a good ground in the rear door for the electric locks to work

This is in the rear load area: