Part number for spare tire tool kit

I can find everything but that piece. I even tried to cheat, and looked to see what they call it in other cars. My old IS300 was the only other car I knew for sure had it and it was just referred to as a "cushion". In the C they call the parts above that the cushion. I have had great luck with Lithia Toyota Parts in my parts searching for other cars, maybe shoot them an email.

 

I take that back:

From a 2012 Aqua search:
BOX, DECK FLOOR, FRONT
64991-52010 (12/2011 - 10/2012)
64991-52011 (12/2012 - 11/2014

From a 2016 Aqua search:
64991 BOX, DECK FLOOR, FRONT
64991-52011

Trim level may change things a bit too. The "box" looks less like your picture and more like molded plastic, but these diagrams aren't always that accurate. Hope that helps.