I just got this and was pretty excited about it since my dog slobbers all over the window and door. It comes with 2 guards for both rear windows (or both front windows) and the material seemed resilient enough. It at least didn't seem like it would fall a part after a week of use. The pocket seemed nice and, although I wished they had other patterns/colors for the top part available, it still looks cute and nice in my car. I also liked how they are long and cover the door almost down to the seat.
The huge problem is how they are installed, so there are four thin plastic pieces attached to the door guard and you slide them down into the slit where your car window is. However, it wouldn't stay inserted in the window slit. I suppose if I never rolled down my windows it would work, but my dog really likes to stick his head out sometimes. Also, even with the windows rolled all the way up, I tried to re-insert them and they wouldn't go into the slit (something seemed to be blocking them). So, since I couldn't even get the plastic parts to slide all the way down into the window, I decided to return this item. The plastic pieces are also pretty flimsy and I could see my 65 lb. Pitbull easily pulling the door guard out of the window.
I really encourage the manufacturer to find a better way to install these in cars, and I'll probably buy them again.