I have the Frontrunner Slimline II roof rack and roof rack real estate is hard to come by with a rtt and solar panel mounted. Recently picked up some waffle (frp bridging) boards and mounting them in a useful/accessible spot was challenging. I think I found the perfect spot, under the roof rack. I used aluminum z bars, ss hardware, and tapered the fitment where it sandwiches the front end and slightly wider opening in the rear. View from top. Glass clearance. Glass clearance different view.