Out and about for something we forgot (!) at the store yesterday. Driving along we heard this loud tone. It was almost like something you would hear from an iPhone only louder. It sounded like it came from inside the car.
Neither one of us know what it was. My phone was plugged in at home recharging. I wondered if it was some kind of alarm but nothing happened. No air bag deployed. No signals on the dash.
I doubt if we'll ever know.