I did a DIY solution using 52mm chromoly tube, same as the rollcage on the back. It’s supported by the bottom of the standard defender tub, where the horizontal support braces that hold the tub to the frame hage u bolts to hold the mounting plate of the rack. I’ve seen people put the cage/rack on the end/top of the tub instead, but I’m not an engineer, so couldn’t be sure that it would hold the weight over bad roads. Access is everything! That and weight distribution.