I had a similar (plastic-molded) setup in the back of my small SUV (similar in size to the Land Cruiser) a couple decades ago. The nicest feature it had were drawers that slid under, which allowed me to carry a huge amount of stuff, out of sight from prying eyes. When I sold the truck, it seemed there was more stuff in those drawers than would fit into the entire back of the truck, like a Tardis.
Nice construction!