While reinstalling the rear diffusers I found a wired connection... little square about 1"x1" under the rear bumper cover (likely revealed itself when body shop reinstalled rear bumper cover). It is sitting, exposed, about in the midle of the cover.
What is it? Sorry, no picture.
I'm thinking it's a connector for brake lights in the event I hook up a trailer. I haven't checked... but may be license plate lights.
Thank you.