To be able to carry heavy loads on my 2010 I did the following: Subaru part # E361SAJ800 4 clips that attach to factory crossbars -about$25. The crossbars on later years seem identical to those on the 2010’s so all gen 4 should work and probably 2015’s as well as they seem the same. Go to hardware store and get 4 3 1/2" threaded bolts that fit in the clip (it you want a convenient tie down point get threaded eye bolts) , and fender washers. I wanted to fit 4 whitewater kayaks so made crossbars 60" long with a stacker. I used straight grained ash for my crossbar so it is only 1 inch thick plenty strong but relatively light. Fabricate spacers 1/2 inch wide to fit over the clips to clear factory crossbars. Place clips on factory crossbars as far apart as possible. Measure where you want to drill the wooden crossbars so as to line up with the clips, then thread bolt into washer then through crossbar, spacer and into clip tighten a bit. You will now notice that the wooden crossbar extends past the plastic supports for roof rack. Because of factory design you need two different thickness blocks of wood to place under the crossbars between plastic and crossbar mine are 1 " and 2" thick. Tighten the bolts they will press the wooden blocks between crossbar and plastic roof rack supports. If you get it right you don't even have to attach them with screws to the crossbar the pressure will keep them in place. This will give you a rack with no wiggle at all. I’ve carried heavy loads of lumber with this set up no problem. Mostly I carry 4 whitewater kayaks. It helps to be tall to put these on but it’s easy to pop them on and off.
