D rings up the walls in the cargo area

[bkw]

I wish there were some kind of solid D rings somewhere mid way up the walls in the cargo area and not just on the floor.
I'm always wanting to put a single paint bucket or a single gas can in back, and in both cases need a way to hold it upright. But there's nothing but weak plastic bits to hook to anywhwere but the floor.

I have to get kind of ridiculous creative with bungees and S-hooks, super convenient and quick to rig up every time...