2021 M3: strange sound while driving or standing still, sounds like a howling dog

[RedTessie]

Hi community, hope someone can help me with this before I can drop the car off at a service center.

Today i noticed a strange howling sound coming from the front / trunk (heat pump possibly?). It happened after approx. 1 hr of driving and repeated every minute or so. Has anyone heard this sound before and knows what it could be?

Cheers

 

[RedTessie]

https://soundcloud.com/eau_eau%2Ftesla-m3-strange-sound%2Fs-ARB0a4qzvUn

Managed to record and upload it for you to hear.

So this sound started after 1h driving in a rainy 10°C and would occur every minute or so for the remaining 1,5h of the trip. The times I didn't hear it was during Supercharging / parked.

Curious to hear your thoughts!