"Metallic" noise inside C70 Coupe

[CoupeC70]

Hi,

I recently had my dashboard repaired due to squeaking and rattle; all the mounts were broken. While the dashboard was squeaking/rattling, there was another noise present that I always assumed was related to the dashboard issues. Unfortunately, that specific noise has remained even after the repair.

The Noise Characteristics It sounds rather "metallic" and seems to occur slightly less frequently now than it did before the repair. It still sounds like it's coming from the direction of the dashboard on the passenger side, but it is extremely difficult to pinpoint.

Before the repair, I thought I could reproduce it by smacking the dashboard with the palm of my hand. However, that doesn't work anymore, and I’m starting to think that the noise I reproduced back then wasn't actually the specific sound I am hearing now.

A few months ago, while cleaning the car/windows, I touched the C-pillar on the left side and heard the exact same noise. The C-pillar cover is loose; I was able to tap against it and trigger this "metallic" sound, so I was fairly certain that was the source.

I placed some foam under the C-pillar cover to stop it from moving so much, but that didn't help much with the noise while driving. I wanted to investigate the C-pillar again recently, but now I can no longer reproduce the noise at that spot manually.

When it Happens I should note that the noise has become less frequent overall since the dashboard repair. However, that might simply be a coincidence...

City Driving: It occurs very rarely, perhaps only when driving somewhat briskly over bumps or potholes. It is very intermittent.

Highway: It occurs more frequently on the highway.

It seems that speed plays a role in triggering this noise. Is there anything under the C-pillar that could be causing this noise? Could there be any other potential noise sources located around the dashboard area, specifically on the passenger side?