So if you've seen my video of my explorer flexin the back window is moving so much you can put your finger in it. I've heard that you can buy some foam from like home depot that has adhesive on one side to put around the window to help keep some of the pressure in. One of my buddies did it and said it made a big difference, just seeing if it would be worth it, because I don't want to make it so tight that the pressure breaks the window.