Other than dealerships .. where would one go to purchase small interior bits online?

Specifically .. an expanding nut that goes behind the upper left plastic interior trim (where the rear window is). The philips head screw that attaches to it also attaches the round anchor bit that holds the cable that raises the rear parcel shelf when the trunk is open.

 

Why would anyone other than a dealer have them?

 

That's why i'm asking. I'm currently not anywhere near a dealership.

 

Google is your friend. There are plenty of sites that carry the same part numbers. Try calling a dealership and asking for the part numbers, and then look for them online.