Purchased this for my 2011 RAV4. This is the perfect size for this vehicle. When place as far back on the roof (right in front of radio antenna), the cargo box stops right before the curvature of the roof starts going downward at the front of the vehicle. I believe this minimized air getting caught under the cargo box and creating drag. While driving, I haven't noticed anything different. Fuel efficiency is about the same. I am sure this would be different if there was some cross-wind, but nothing of that happening in NYC during this review. The weight of the box is very light. Easy enough to be picked up by myself. Installation was quite easy, 15-20 minutes to install with no additonal hardware required. Since the RAV4 has a hatchback door, it was easy enough to stand on the rear bumper to access the cargo box. The construction is OK. The shell is made of semi-hard plastic. There is definitely flex to it. This product is not made of hard plastic, but I am sure something like that would have cost twice, maybe three time more. For the cost and size of this cargo box, it is a good buy. I was lucky enough that this box fits perfectly for the RAV4. I wish we could upload photos here and I would show how aesthetically pleasing it looks on my RAV4.
X-Cargo XL - great price, disappointed with durability, wind noise and wind turbulence. I bought this product due to the price and reviews. However, I am disappointed. Driving while it is empty is NOT an option. It bangs against the roof at speeds over 60mph (I had to do this because I purchased out of town due to availability locally). Shakes a lot at almost any speed. Even when full, noticeable wind noise in cabin of vehicle, not too bad but I can definitely tell it's up there due to the wind noise and drag. Lid is very cheaply made, flexes a lot when opening. Haven't taken an actual trip yet over 100 miles but planning on one soon. I do not have high hopes I'll be satisfied with this unit and will likely return if a longer trip, loaded, does not yield a change in my review.
For the price, you really can't beat this box. Used for a trip to the beach and was pleased. Everything stayed dry and secure on a 6 hour drive through rain and intense sun. Only issue was with some continued sagging of one of the lifts. Seems like a build quality issue, but again, at this price, compared to 600+ for a Thule or similar, this is a great box.