Design
The Skybox Pro won’t win any awards for aerodynamic design: it follows Yakima’s aesthetic that’s been relatively unchanged for over a decade. However, it’s inside the box where this box shines. Start with a quick-release clamp attachment (think, bike wheel) that cinches tight in a split second and doesn’t stick up into the cargo space like Thule’s does.

The Skybox comes with a pad that fit between the rack attachment hardware inside and protects ski and snowboard edges from cutting the box’s floor. Tie-down clamps line either side of the box’s floor and a standard cargo next will hold tight anything.

The locking mechanism uses a lever to open, but it felt redundant since you can’t open the box with out the key anyway. It would’ve been nice to access the closed box without the key, or do away with the lever, which sticks out from the side of the box and will affect airflow.
The Yakima was the burliest construction of the models tested this season (Winter 2013)—that equates to more stiffness, which translates into easier opening and closing/locking.

Installation
I was able to throw the Skybox onto my roof by myself, but it wasn’t easy. It’s really a two-man operation since the box is so much more cumbersome than either the Thule or the Rola tested here. This was even more apparent when I removed the box from the top of my minivan. It slipped and dropped onto my driveway, which scratched the Yakima’s gorgeous onyx-black top.

Yakima’s rack attachment hardware isn’t as quick as Thule’s, but the quick-release system is nearly as simple. I spent 10 minutes positioning the hooks to fit my crossbars and tighten them down. I suspect that after setting the clamps’ position, I’d save around 2 minutes in installation time. Removal, however, beats the Thule at less than 2 minutes.

Cargo
As stated above, the Skybox shines in terms of a clean cargo space inside that maximizing available space. It easily swallowed my snowboard, skis and boots and from eye balling it, I’m positive that I could’ve fit 4 sets of skis/poles with 2 snowboards layered on top thanks to the Skybox Pro’s 16-inch height. It’s a cargo monster.

At 92 x 36 x 16 inches 5 inches, it’ll suck up a van’s worth of snow gear. Yakima is reluctant to provide a max weight capacity on the box since the max capacity of a car’s rails determines how much weight can be stuffed in the box. For example rails on a Subaru Outback have a max capacity of 150 pounds, which equates to a 98-pound load limit for the Skybox.

Vehicle Fit
Due to its super-long length, the Skybox Pro 18 would look ridiculous on small hatchbacks or sloping rear window type vehicles (although the Skybox’s 24” minimum crossbar spread would work on those vehicles). However, the rear overhang would likely prevent the hatch from opening completely.

On the Road
Because of the box’s relatively high profile, I could sense my van struggling to reach highway speeds from a stop. Crosswinds were also noticed.

Value
$649 buys you the one and only cargo box you may ever need, assuming you don’t crash your car or run into a low-ceiling garage. Still, there are less expensive options out there that suit that description as well.