We used this carrier on a ~750 mile road trip, almost all interstate highways. It worked well and showed no signs of wear after the trip. We didn't use the door hooks, so I can't speak to those, but it was very secure on the rack rails. Based on observing other's vehicles, I'd have to recommend filling it up as we did, or if not full, use the extra straps to cinch it down tight so it doesn't flap in the wind and become worn.
As I think others have noted, be sure to orient it correctly to prevent stressing the zippers.

I loved it!! Great material, very easy to use, love the fact you didn't need roof rails

I recently purchased this rooftop cargo carrier, in preparation for a 1,000 mile trip to Florida. It arrived in good condition, and it didn't take long to figure out the directions and strap it to the top of my car (I also bought a rubberized mat to place between the carrier and my rooftop, to protect the paint from scratches).
The carrier is quite roomy, I think it fit something like 7 suitcases of varying sizes. And when strapped down tightly, it didn't produce much wind noise either (it took a little trial and error to figure out where/how to tuck some of the straps so they didn't blow in the wind and smack the roof of the car.
My primary complaint concerns the front of the carrier, and how it closes. The zipper runs from one back corner up the side, across the front, then down the other side to the opposite back corner. And there's a flap that covers the zipper, with velcro to keep the flap down and the zipper protected from the elements. But the front center of the flap lacks velcro, so the wind stream coming off the top of the car lifts the flap there, and exposes the zipper. That became an issue when we drove through a heavy downpour of rain outside Daytona Beach, as the exposed zipper couldn't stop the large volume of rain from penetrating into the carrier bag itself. I wouldn't go so far as to say the bags inside were soaked, but they were certainly damp.
If the makers of this product would place a velcro closure, or better yet a cinch-down strap, in the front center of this carrier, I suspect that would fix the leak issue and make it a great product.

This cargo bag for the rooftop is perfect for vacation travels . It's light and roomy and holds anything that you can't fit in your trumk

This saved us from taking two cars for college move in. Held those large ikea blue storage bags. About 3 of them plus other things. Easy to install on the car too. After the trip it did not look weathered and held up great.