I went out for a drive today to meet some friends and when I got close to the destination I heard a loud buzzing from the back of the car. It stopped before I stopped the car. I was running late so I didn't investigate. Then on my way home I heard the loud buzzing again. It persisted even after I stopped the car. I went to the back and discovered the noise was coming from a cordless tire inflator in one of the cubbies. Somehow it was getting switched on an off.