Not particularly sturdy
The box is super practical because it can be set up or folded away in no time at all. Plus, it fits well even in smaller boots.
Buuut... the mesh is very easy to tear, it rips super easily. So if your dog gets a bit rowdy, the mesh is gone and your dog is running all over the car.
Our Aussie has already destroyed two sides, and the box is only 2.5 years old. Now, with the holes in the mesh, it's no longer usable and has to be disposed of at a high cost :(