Have a 2014 Limited and have been battling this noise for several years. Have taken it to the dealer and one one occasion after 3 hours of looking at the car, Tech did actually work on it for 3 hours, they told me my rear seat was not latched and sent me on my way. As I drove out the dealership, it continued to make the same **** rattling sound. Dealer was useless.
I did notice this afternoon that the pathetic plastic nuts securing the inner fender liners on the right rear will not tighten. They will snug finger tight, but try and tighten them any more and they just turn like as if they were cross-threaded CHEAP plastic tabs.
UGH!!