I own a 2012 Outback and there is a short 1-2 second buzz coming from under the driverside passenger seat when I close any door. Sound like a small solenoid or motor. Yet could be just an aluminum heat shield with a loose bolt that is vibrating. It does seem to be longer if I close the door harder. There is a plastic mud guard on the underside that I have not removed yet. But the noise seems to be under the body structure and not under the seat on the inside of the car. Anyone had a similar noise?