Trim rings yes, or also known as beauty rings. Toyota calls them wheel ring caps because Toyota hates using normal names for parts. Toyota calls a hub cap wheel hub ornament sub assembly.

 

At least on the model S the 19 inch tempest wheels do have covers but the alloy wheels underneath actually look really nice uncovered (ones in this photo don’t have center caps but they’re available):

 

Ha, I had a 1979 BMW 320i in high school with steel wheels that came with chrome beauty rings.

 

my first car had wheel cover but after that none has had it. The only plus is as Steve said it’s cheaper to replace/repair.
Unfortunately they do. I think 19” is the one with cover. I thought it looked odd and my friend told me yeah it’s wheel cover. 20” and 21” don’t but the ride gets worse. So some sacrifice for the ride quality and buy aftermarket covers that resemble 20” and 21” at least the color.