GR Yaris Rattling Noise coming from Rear Bumper (alignment clip issue?)

[JAA NE]

Hey guys, just hit 50xxxkms on my 2020 GR Yaris, and all of a sudden have had some rattling noise coming from my rear bumper- seems a lot more loose than usual. Seems like the 2 alignment clips had slipped out. I popped them back in but as soon as I drove off the rattle started again, so I feel the clips and clip mounts are wrecked. Anyone know where I can source these for cheap, or have any alternative fixes? Toyota servicing wants $250 AUD for 2 plastic clip mounts lol

 

[Altocumulus]

Have you checked that the plastic wing nuts in each rear wheel arch are tight? A torch helps to find them.

They come loose over time, leading to a rattling noise from the rear.