Where does this part go?

From the left back seat area look at the extreme rearward end of the plastic trim over the inboard front seat rail. The cover is on top of the trim over the rail.
I don't have piece 15 on my center console. I have a 2014 TH with cloth seats so maybe different trim levels are different.

I had to correct my Post #7, so Mark_ s quote is no longer correct.

I'm still confused, but I'll get over it. My whole life has been confused.