We had a rattle that we tried fixing over three services.
1. They took apart the back seat and re-lubed everything and readjusted
2. They then adjusted the hatch and tightened everything up, still happening
3. They finally decided for the tech to go on a ride-along to hear the noise I was talking about. Immediately heard it. They found the rattle in the headrest in the back seat.
It sounded like a metallic squeal. It was pretty loud, but thankfully it was finally fixed by a technician who heard the same sound and told me he would get to the bottom of it.
It looks like you're in Berkeley, we took ours to the Berkeley service center the three times. IF you get matched to one of the good technicians and they verify the noise, you'll probably be able to get it resolved.
The way we reproduced it was to drive west on University Ave from Frontage towards the marina. The technician said he would try some things, drive down that same road to verify it fixed, otherwise he would keep trying it. It took two full days, but he got it!