Help searching for the "Backend Banshee" - 2015 Prius V

The Banshee is a very loud and frightening but mysterious crashing/grinding scream that seems to emanate from the right rear of our 2015 Prius V when we pass over small (2cm) depressions in the road at between 40 and 65 kph, usually at times of warmer weather. At times, we hear a simple "clunk", but at the worst, it's an awful metallic grating sound.

Over the past 4 years, several garages have attempted to catch the Banshee, but none have succeeded! We've had the shocks replaced (twice), and the rear brakes "looked at".

We've compiled dash cam encounters with the mysterious beast over the past half year. Any ideas what it could be?

 

We think we have a resolution to this issue. Our previous attempts involved independent garages, but this time we went to the dealer. This is how we described the problem per the work order:

Customer believes there is a problem with the rear suspension. It only happens when it is getting warm out. There is a loud clanging noise when going over potholes, railroad tracks, or any depression in the road. Please check and advise.
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The invoice records the Tech response:

• Tech cause: Test drove and heard the noise.
• Checked and found e-brake is grabbing the wheel and making awful clanging noise. Removed rear wheels, cleaned shoes, re-adjusted. After repairs, went for test drive again and confirm noise went away. If noise comes back will need to replace rear e-brake shoes, hold down kit and rotors - Toyota parts.
• Tech comments: Completed ...

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We've now had several days and the problem seems to be licked. Hopefully for good!

BTW, I didn't know that emergency brakes had shoes separate from the regular rear brakes. Does anyone know how these work, and whether they are peculiar to the Prius?