Chuck,
I have a tonneau on my 58 BN6 and there are no attachment points on the door. The tonneau does flap a lot in the wind when I leave the passenger side attached while driving. I have been trying to figure out a way to get rid of the flapping, without installing another attachment point on the door. The tensioner sets, like you see on the 4 seater tonneau's, will not work. I am considering sewing or somehow attaching a piece of aluminum(lightweight) wrapped in vinyl, to the underside of the tonneau on the outer edge, where the tonneau almost covers the aluminum trim on the door. If it is long enough, it should keep the tonneau from flapping.
Do you think this would work?
Robert