Hmmm.. I've had the same problem.. New 4.4 w/ sport package - rattle from the back (right) rear area. Actually sat back there with the G/F driving and of course, no rattle.. Hear it every day. Checked the tire, no. Checked the plastic slide that folds over itself on the bottom part of the hatch, no. Tried the shades - rear and sides, no. This sux.
