I thought the same. I thought they were only on the cargo.
Mine is an Air Defence. When I started looking around to see where I could splice a civvy trailer socket into the loom, I found it. Since then, every one I have looked at (not many) since has had the civvy trailer plug, if not on the rear cross member on the back of the Perentie, on the rear cross member on the inside of the rear wheel arch.
Maybe it was a mod yours didn't get.