Yes, I am thinking of using the soft top rails. I have not had a problem with the rail system with a full Bestop cover, even at 80-85 mph which is about as fast as i have ever gone in the D-90. I believe the Badger works tub cover uses the rails as well but 1 I can not afford those covers, and two, if i can get all together, I will have a bench seat down one side of the tub, and a locker system down the other side. The tub canvas cover will go over these as rain and somewhat privacy protection.
Or I guess I could bolt on the L type brackets you see on the SIII and UK military LRs and rope it down.
I'm contemplating thinking about thinking about it!