I have the solution! Go to your Ford dealer and get part # F4TZ-1504366-A. It is a metal bracket which replaces the plastic one in your dash that is probably broken.
My dash rattled terribly until I put in this bracket. Took me about an hour start to finish. It comes with instructions and the rivets that you need. All you need is a socket set, screwdrivers, a drill, and a pop rivet tool.
Thanks to Wish for giving me the tip about this. Just wanted to post it here in case anyone else has the same problem. Oh, and the part only cost me $14 or so.