This is a big box. The center "belly" area fits a milk crate with room for sleeping pads above. Before short skis were the rage this was one of the few boxes that would carry my 215's (just for reference, they've since been retired). Now - with 3 kids, 2 dogs, and a busy schedule this roof top space is invaluable for pack'n'plays, kid carrier packs, fishing poles, joggers(collapsed), firewood, chainsaws, you name it. Not once have I had to unpack it a little, I laugh every time I hear the latches engage because the amount of stuff it just consumed.
Take your measurements twice since the length of this dictates that you'll need a rack whose front portion can mount, or slide, forward enough so the box doesn't interfere with the vehicle's hatch. Funny, in the picture above the hatch would not open all the way - big pain.

Can't speak much of durability as I've had this for only a few months, but as a cargo box this thing is amazing. Most inexpensive of any out there and still manages to hold almost anything you throw in it. Bought this mainly as a way to free up space in my Jeep that was being taken up by all the odds-and-ends I had inside... tow straps, jumper cables, tool kit, etc. On a recent camping trip I was able to fit all of this plus a few packs, full size camp stove, multiple tents and sleeping bags and a few other miscellaneous items.
As mentioned, be sure to take measurements of your rack to make sure it will fit... mine just barely fit on my 2008 Jeep Liberty with the rear hatch pressing up against the box a bit when fully opened. Aside from that, the only disappointment I've had is not having bought one any sooner!

The best box ever. Bought this years ago and had it perform w/o problems ever since. Use it during winters for all the outdoor or dirty gear, from skis to muddy boots. The two latches are easy to operate, even when you can't feel your hands. Similarly, the hinges are sturdy and have never broken or refused to open. Highly recommend for the gear-head or family mobile.