I'm trying to figure out a solution to an organizational problem (usually something I'm pretty good at, but I'm having trouble).

I'm currently driving a Toyota Highlander with three rows of seating. The last row is always folded down, because I carry a lot of random crap around in the back of my car for work (lots of spare cables, tools, a couple routers, etc). The problem is that I frequently want to carry more than five people in my car, but can't because it's full of junk.

What I'd like to do is to have all this stuff in a storage container that can sit in the back of my car, but in a pinch I could take it out and put it on the roof instead. I don't want a permanent container on the roof, because it's not as easy to access, I don't like the look, and I want to fit into garages

Does anyone know of any such thing?

As far as alternatives go, I found this, but it doesn't hold much.