The wing panel is the portion of the carpeted floor under the closest storage box. It extends the usable floor to the slidding door, making use of valuable space that previously was wasted. The previous photo shows how it is held up.
The right end of the wing panel is tapered so it clears the cup holder bulge in the sliding door. Getting the taper right involved numerous closures of the door and measuring distances on a cardboard template. When the door is closed, it comes to within half an inch (1.2 cm) of the wing panel.
A later modification (next two photos) elminated the three support posts seen here.
