Soft, light and strong-your minivan's storage.

This is to illustrate the cube position in the van.

With a 2x2 grid beam frame constructed inside your van, you can hang your soft furniture, cargo-nets, curtains, or lights up high to conserve floor space.
By adding extra vertical and horizontal beams you could easily make a false floor / bed or shelves (please use 1/4" plywood) Pretend your van is an airplane and you need it as light as possible!
When I was almost young, I hitchhiked across the country and I remember hearing someone say they preferred a soft rucksack to a framed backpack because they could squeeze it into places where a frame would get stuck and that the frame was uncomfortable to lean on in a crowded vehicle. I like (removable) 'soft "cabinets" like on the Cabela's Camp Kitchen.  Why fill up the limited space of your van with heavy hard furniture? Here are some examples of soft storage systems:

This german van has kind of a grid beam "Airline Track" attached to the interior to attach things.

See the hanging storage system.