What is this (wheel well liner/mudflap) ?

This may seem like a stupid question but the Toyota dealership parts guy has no idea. I'd like to replace this shredded piece of plastic behind my driver side rear tire but don't know what part it is and neither does the dealership.
Thanks in advance

 

It just looks like a part of the plastic fender liner.

 

Yeah me too but the parts guy can't find a 'fender liner' or wheel well liner part in his inventory, diagram, whatever he's looking at. I've tried looking online and can't find the part either.
I should note this is a 2011 4Runner SR5 if that matters.

 

It should be listed under rear wheel or quarter panel liner or apron.

 

ok thanks, next time i'm there i'll have him look that up.

 

https://www.carid.com/2019-toyota-4...quarter-panel-inner-structure-2769848012.html

 

It looks like the previous owner hacked up the mud flap in order to fit bigger tires. This is what OEM looks like.

 

^^^^^ That.
It WAS a rear mud flap that the previous owner cut off.........

 

Or just get a set of Revtek delete kits..

 

and clearly whatever he/she did, did it poorly as the tire still rubbed anyway