Update from original post. Finally got to the service center due to covid and had them look at it. They said they tightened some stuff, but on inspection only saw some dirty finger prints on the trim. Still have the problem. May try going back in the future.
I’ve had noises in the back since receiving the car. No real improvement after 4 service visits. I think these are fixable problems, but requires perseverance and expertise, which I think is not typical in their service dept. They seem rushed wanting to get the car out the door. Regardless, it’s a little less loud now, especially if I drop the back seats.