Duct tape! As long as you don't leave it on for a loooong time. It will be leak free for a camping trip. (trust me, that CRAP will turn to concrete if left on too long). I'm talking 3-6 weeks in the HEAT!
Go camping, have a good time, make memories, THEN remove the duct tape from around the
windows as soon as you can (like the day or two after you get back!)