It just tucks behind the seat. The only spots that can tuck tightly are right at the seat corners. Mine billows if there is a stiff cross wind. Regular driving on not so windy days does not seem to cause the billowing.
I have seen others put snaps along the back side of the seat, but this would not be stock.
My original boot fits tighter than my other car with the repop boot.
Oh, and mine has never blown off, just billows and creates a parachute until I pull over (usually quite quickly).
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold