Source for "white rectangular keyed push nuts" on back of foot well trim panels?

[Pliny]

Does anyone know of a source for the white plastic part highlighted in red in the image below?
I already asked Benny and as far as he could determine they aren't available separately, only available with the foot well panel itself.

I've removed and reinstalled those panels a couple of times (Armorlite, connecting to the ground studs) and I've broken off a couple of the prongs that hold the white thing in place in the hole in the trim piece.

Thanks.

Sponsored