Those bins look perfect. Can you tell us what brand and size they are?
To continue the thread sidetrack, as Rob said, they're the 8GL Action Packers. They are pretty much perfect for that space and we use them when sleeping inside the Xterra while camping. They've become more expensive now, and they're not the strongest box or most efficient shape, but they're hard to beat for that purpose. I highly recommend them if you want something to create a flat sleeping area. Our '09 Xterra even came with some included in the purchase!
Note that unless you're short and have the front seat far forward, there is not really room for them in the rear passenger footwell when driving around. This is typically how I have them, you can run a strap through the forward seat bottom and child seat loops. I have a series of pics showing the setup that I've been meaning to put together in a separate post. Maybe I'll work on that this week.
To make them more useful for smaller items, check this out:
I have posted this before but I figured I'd share it here, as many people have found it useful. The ubiquitous 8GL Action Packers that are so handy for gear, as well as being perfect to create a flat sleeping area in the back of the Xterra, can be improved for about a dollar and a little time...
www.xterranation.org