So, I'm trying to use a universal rotopax mount with an FJ cruiser factory rack. The question is how can I mount the plate to the crossbars on the FJ rack? I thought if the backing plates are stiff enough, I can just tighten the bolts down between the crossbars for a firm fit. As you can see in the photos, the backing plates are not stiff, and bent in between the crossbars. Next, I'll try 3/4 inch hollow steel bars, which may do the trick.