Retainer
My retainer was under the headliner when I cut it. Pop out your overhead lamp and see if it's there. There are writeup on how to make a harness, and you can probably get the retainer cheap for a dealership.
As hard as the 2005+ versions are to find, if I wanted it bad enough, I'd jump on it. At the time, my 04 was hard to find and when a cheap one came up, I snagged it.