Colorado David
Explorer
Some folks that we traveled with had adjustable Load 'n' Lock rails kind of like these
Which were pretty cool and made the load area highly versatile and very secure for their modular packing system. I don't know if there is anything like that available here though.
Those are aviation cargo tie-downs. They would be very cool in a vehicle, but I suspect they would be expensive. I used to have a bunch of them for setting up my camera gear in a Cessna Caravan. I wish I knew what happened to them. I would still need the rails, though.