Hey, I finally have a PN to contribute!!! Multiple people have told me they've damage this part, so here are the goods....
The PN for this part (see pic) is 55054-7z001 and is decribed (on my invoice) as a "Seat Assy - Rear". The same part is used for both sides.
Local dealership charged me $21.76 and had to order them (took 4 days).