[FKHeath]

I believe this is it: Rear Bumper Applique - Clear - Xse | Part #PT92942200 | Toyota Auto Parts

It goes on the hatch threshold to keep it from being scratched should you drag something across it.

Edit: since that is rather thin (like the PPF up front) it really does not protect very well. There are much heavier duty rear bumper protectors. I don't remember where I got mine, but it is similar to this:Pardon Our Interruption...

much, much heavier.

 

[FKHeath]

No one ever puts PPF on the rear bumper cover because it is not needed there. Rocks don't hit the rear. That is why PPF is put on forward facing areas, even the "front" of the outside rear view mirrors.

For that reason, it appeared to me that what the OP said was on the rear bumper must be the factory accessory I cited.