I thought some guys were reporting cracked windshields from improper install? I'd have the dealer check it. It might be covered by warranty if no damage hits are found.
Ratchet straps, gloves, rope and a small tarp. (I have a bed rug I don't want to mess up if I can help it.) And now the bracket from the tailgate because I installed a tailgate assist.
Can you tie a small rope to something behind the seat and over the belt to pull it behind the seat? Then it won't have the air space between it and the back wall to start flapping. In other words, it would be tucked behind the seat then come back over against the seat.