This has me baffled. I first heard this noise which I thought was electrical and I went so far as to remove the main battery to the vehicle which did nothing as the noise continued. It is completely random in its coming and going. I walked past my car 3 weeks later and the noise started again, drove it yesterday and it wasn't there.

I used my phone to record the sound which appears to come from around the firewall near the center of the windshield.

Help