I see there that you made a splint for the cross bar, a constant reminder of your brain fart <img src="/forums/images/graemlins/notooth.gif" alt="" />!!
As far as that flap goes you could always put like four snaps to keep it from flapping, its not like it would be much work now that you have all the tools.
Yeo every time I see that brace it reminds me of my own mental flatulence.
However, after having it out on the highway, I must say that in the end it is a good thing. By cutting out so much of the middle, that cross-bar is pretty flexible, abd bounces/flexes around a lot. that upper corner section is hollow. I ended up not only putting a metal bracket above and below that section, but also wedged in a peice of plastic inside of it to add rgidity, and flipped/capped it wit hfiberglass filler. That stiffened it up a lot.
Again, thsi really is only b/c of cutting out the middle. Just a half-cab like DCG's wouldn't have that problem.
I might still ru na strip of 1/8" steel across it, just so I could use it to support/carry large items later.
re: flapping - it turns out not to really be a problem. The snaps that are there are within about 3/4" of the end of teh fabric, and it's pulled really tight. I had it up > 75mph yesterday w/o problems.
One problem did arise though. In teh front, the snaps are on top, running horizontally acros the cabin. At highway speeds, it wants to catch a little wind underneath the snaps, and the center snap came undone. I think a quick/easy fix for thsi will be to afix a low-profile wind-chammel right in front of it (like are often in front of sunroofs).
I was suspicious that would happen, it was my primary hestitation on attaching the front that way.