This black panel attaches to the threaded rod that secures the mini spare tire in the trunk. It fills in the gap between the mini spare tire and the spare tire well, so the factory carpet can lay flat. If you don’t have it, the carpet falls into the wheel well.
Many times this cardboard filler panel is missing, damaged or destroyed.
First photo shows the actual panel. Second photo shows the carpet pulled up, so you can see how the panel is secured to the spare tire. Third photo shows the panel in place with the carpet laying down flat.
NOTE - This panel is a black cardboard piece, but appears grey in the photos because of lighting.
A nice finishing touch to any trunk interior restoration!