I have a 2015 Dodge Challenger SXT. When the engine is off it sometimes makes a high pitched beep/squeal at regular intervals, usually a minute or so. The noise lasts 2-3 seconds and almost sounds like an old computer connecting to the internet.
This continues for hours and is random. It does not happen 24/7 while the car is off. I notice it after I wash my car, but maybe that is because I’m around, drying, waxing, etc.
In this video, I have not driven the car for 3 hours. https://youtu.be/W3H14rplzsc