I used velcro for a little bit but I eventually used the small buttons that came with the topper.Measured and drilled holes, then screwed those three buttons into the bed. Very secure and it keeps th eplastic from rubbing up against the window. I got some big plans for the topper by ditching the folding aluminum frame and putting a steel frame in its place so I can put a RTT over it.
Sorry for the pavement pics, but here are some recent pics of my 3rd gen at some military bunkers near the Golden Gate Bridge in SF.
some military bunkers near the Golden Gate Bridge in SF.
Good shot of my buddy Jon, going up!