I have also been experiencing the same rattles. I've had the lower latch replaced because it had play in it....and this seem to fix the rattles. Then after a few days of driving, the new lower latch began to develope play and the rattles came back.
The SA did admit to me that this is a known problem and design flaw. And the only real fix is to have the bump stops for the upper gate adjusted outward so that when the gate latches on, it will pull in and have more tension on it...and hopefully stopping the rattles.
Well, Ive been back to forward with the dealer and the rattles are still there. And, it has gotten a lot harder to close the upper gate as well