Hello, I'm not sure if this is the right place for this issue but I'm gonna give it a go.

So a few months ago I've been hearing this strange sound on my car ( CLA Coupé 2021, brand new). The scratching sound you hear at the end of the video's (https://imgur.com/a/3UEaVHo)

You can hear it when I unlock my car with the keys or open the door, any door even the trunk. I've already brought my car to my Mercedes Dealer 5 times.... but everytime they say ' we can't find anything so here's your car ' and the issue is not fixed.

It doesn’t happen all the time so that's the hardest part. So it randomely happens, it comes and goes as if it's living it's own life. I can hear it for a week straight & then it can disappear for a couple weeks again. And then it just randomely comes back. This has been happening since June.

So in the morning, I open my door and I hear the scratching sound. I close the door and open it again and it's quiet. Then, after work, I unlock the car with my keys and I hear the sound again. I can never hear it all the time, there always has to be like 5-6hours inbetween before it happens again. So closing & opening the doors or unlocking the car over & over & over wont work to keep hearing the sound.

I'm literally clueless and I don't know what it is, but it doesn't sound healthy at all. I'm still under warranty and I also got the Complete service contract with Mercedes for the next 6 years.

I really don't know what to do anymore, I hope one of you recognises this sound and could possibly help with this. I first thought it was the fuel door maybe cus of the 'lock system' so u can't open that small door when the car is locked. But the sound comes from the bottomside of the car. Is this the electric handbrake? Could that be it?

I know it's really hard to find the issue through a video, but hopefully you can help me out.

Kind regards