Metallic ticking sound, passenger side rear

My '17 Prime has exhibited an intermittent metallic ticking/creaking sound since new, coming from the passenger's side rear hatch area. I've taken it to multiple dealers, each of which looked at it more than once. Most of them say "cannot duplicate," while the one that did hear it said it was the tire inflator kit causing the sound. Removing that didn't have any effect, then that dealer, too, switched the story to "cannot duplicate." At that point I gave up on it.

It occurs when the outside ambient temperature ranges from about 30-45 degrees (F). Now that the car is out of the bumper-to-bumper warranty, I have tried to pinpoint the source of the sound myself. I've removed the interior trim panels in the hatch area and from the hatch itself. I insulated the rubber hatch stoppers with felt tape and lubricated the hatch seal, but the sound is still there. Does an intermittent, ambient temperature-dependent metallic ticking sound fit the description of the loose shock nut issue? Are there any other previously-encountered noises fitting this description in this area of the car with known fixes?

Thanks in advance.

 

I've read about that TSB and actually mentioned it to the dealership, but they said it only applies to early 2016 models. Have there been reported cases with the 2017s?

 

Thanks for your thoughts.

The car has had the problem since new and I recently got new tires, so it wouldn’t be something stuck in a tire.

The last dealership to look at the car said they “tightened suspension components,” but didn’t specify what.

I have another service appointment on Friday with the dealer who was able to fix my axle noise issue; hopefully they can help with this. I will follow up with the results.

 

The dealer was not able to replicate the sound and I picked up the car after hours, meaning I couldn't demonstrate it for them. That's unfortunate because the noise was definitely there when I drove away. I was able to capture the sound today in a video (https://1drv.ms/v/s!AhD9s8Useu8ngclRTUH_6AEcS5zhBQ). Has anyone heard a sound like this before? Apologies for how the camera was moving, I was by myself and just moved my phone around in an attempt to capture the sound. I did notice it seemed loudest in the video when the camera was pointed at the passenger's side rear seat. I folded the seat down and the noise seemed to get more faint, but I still wasn't able to pinpoint the source.

At this point, I think I've done all I can do and the ball is in Toyota's court again, but I'd appreciate any input from fellow members if anyone's had a similar noise before. It's getting to the point of being rather maddening; I was on a smooth highway when this video was recorded, and the noise is quite prominent, especially when operating in EV mode.

Thanks!

 

Update in case anyone has this problem: The right rear passenger seat was replaced. That cured the noise recorded in the above video. Toyota was kind enough to do it under warranty at 46,000 miles because I'd initially reported it before the warranty expired.