The Dust-Turd project.
Off to the inside. Removed the rear filler panel (0.80 sheet metal - 6.5 pounds ) and the cardboard / duct tape filler panels for the rear cage bars.
Made new fillers from aluminum and a cross panel to flatten the area under the package shelf.
Found two panels that had no rivets or only thru one panel, might explain the rattles from the rear. Fixed them and made a new package shelf.
Added sound heat shielding over the complete area.