Reviews You Can Rely On

How We Tested Cargo Boxes

Monday November 7, 2022
cargo box - weighing each cargo box to verify the claimed weight.
Weighing each cargo box to verify the claimed weight.
Credit: David Wise

We spent months driving around with these cargo boxes and took them along for all multiple trips during our testing period. Whether running errands around town or on big road trips, we swapped them on and off our vehicles to find their flaws and nuanced differences. Because this review relied so much on the subtle differences and features of each product, we tested them in every way we could imagine and pushed these boxes to their limits. Short of sleeping in them, these cargo boxes were evaluated as thoroughly as possible. Eventually, we came up with what we consider to be the four most important rating metrics: ease of use, durability, security, and appearance.

Ease of Use

Accounting for 40% of each box's overall score, we found ease of use to be the most critical attribute of any cargo box. For this metric, we assessed the assembly, mounting, and opening/closing. Our testers timed themselves on each install, making notes along the way about the ins and outs of each. We enlisted the help of friends near and far, and our lead tester even tried to mount a few by herself (though she doesn't recommend this). We went back and forth between different mounting systems to see how they performed in direct relation to one another and recorded the pros and cons of each. Finally, we opened and closed these boxes a LOT, trying to knock them off their alignment and stuffing them full to the brim. We laid all the boxes next to each other, opening and closing them all to get the most direct comparisons, evaluating every little detail.

cargo box - be prepared for some wrestling if installing your box on a tall car.
Be prepared for some wrestling if installing your box on a tall car.
Credit: Lauren DeLaunay


Our testers evaluated every part of the security system for this metric, from the big questions (is it secure?) to the small (how easy to use is the lock?). We tried to break into each box, knock them out of alignment, and come up with scenarios in which the boxes wouldn't lock properly. We wanted to catch them off their game, but most of these products exceeded our expectations in this category. This important metric was given a 30% weighting in the final score of each box.

cargo box - don't forget to lock your cargo box!
Don't forget to lock your cargo box!
Credit: Jenna Ammerman


We were lucky enough to do this test during spring and early summer in the Sierra, where we naturally encountered everything from sweltering sun to high-speed winds and rainstorms that turned into snow. We followed each other around in our cars to see if the boxes moved with the wind or on hard turns and drove all over northern California to see what sort of wear and tear we could submit our products to. We also looked at how sturdy or floppy each lid was, shaking, opening, and closing them violently to see what they could withstand. This metric made up 20% of the final score for each product.

cargo box - floppiness comparison (left: sidekick, right: sportrack)
Floppiness comparison (left: Sidekick, right: SportRack)
Credit: Jenna Ammerman


While we admit this is a little subjective, we made general observations about the appearance of each box. We awarded higher points for color choices and finishes that hid scratches and bugs (which we sadly accumulated many of during the hundreds of miles we drove). The box's profile was also a big factor here. Because this is a more subjective metric, we only weighted this one at 10%.

cargo box - we know that style matters.
We know that style matters.
Credit: Lauren DeLaunay

We aimed to be as objective as possible during the course of testing, making clear, unbiased observations. Most importantly, we looked at each box side-by-side and judged them in comparison to each other. Every box we tested will get your belongings from point A to B, but we tried to get to the bottom of each product's small details to bring you a comprehensive review of the most popular rooftop cargo boxes on the market today.

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GearLab is founded on the principle of honest, objective, reviews. Our experts test thousands of products each year using thoughtful test plans that bring out key performance differences between competing products. And, to assure complete independence, we buy all the products we test ourselves. No cherry-picked units sent by manufacturers. No sponsored content. No ads. Just real, honest, side-by-side testing and comparison.

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