Recently started to develop this annoying noise. It's inside mainly on the left side. Cannot be heard outside its been confirmed its not anything mechanical under the car. My brother who is a mechanic said it may be the heater box under the dash. I'd need to wait until Monday to get a proper diag. Wondering if anyone had any other ideas? The climate control on the car does not effect the sound.
S3 noise - YouTube
S3 noise - YouTube