Tonneau cover install question

[leeb51]

I am looking for instructions, or at least some good advise, on how to mount the tenax fasteners in the door tops when setting up for a tonneau cover. The dash on my '88 cab has the three spots designated for the dash fasteners (covered with a plug) but the door tops are another matter. I need to determine what length shaft tenax I need and if there is some "magic" to how and where to mount them.

Any assistance will be greatly appreciated.

I know many don't like tonneau covers, but I love them and have used them extensively on other cars. I like being able to jump in withou putting the top down and the reverse when I get to my destination. Also, I think it is an interesting look over simply having the top down.