Well, I've been in the hatch two times now. The rattle is definitely coming from the third brake light. I can't figure out how this thing is attached, so I can't remove it to sure things up in there. If anyone has any drawings or recommendations, please let me know.
Until I can figure out how to remove the light without breaking it, I have put as much foam insulation around the plastic posts that stick through the metal frame in hopes that it will keep the assembly from moving around. So far, it seems to be working.
The strange thing is that now that the rattle is gone, I remembered why I liked the car. It's sooo nice to drive when it's not rattleing.
-ZCarGo-