High pitched ringing after turning car off? Any idea what it could be?

Goes away after about 10 seconds. Its not the headlights, Ive had a few people say the headlights make a high pitch ring. But theyre off in this video. I primarily notice when the car gets turned off. Anyone else experience this?

(Its very hard to distinguish where the noise is coming from, but i THINK its coming from the rear end)