I've located and solved one of two significant rattles in my '13 FFH. The one I've solved was found in the dome-light area. I was able to test that this was the case when I stopped the rattle by pressing the area between the two dome-lights.
In any case, if you (gently and evenly) pull the dome-light down, you'll see a large molex connector secured to-the-car and a small molex connector unsecured and floating about. Guess which molex connector I duct-taped to the roof? You guessed it - the small molex connector.
Voila! The rattle is gone.