Video with the sound

 

never heard anything like that.
is it on even when you switch the car off?

 

Yes I can here it through the door when the car is turned of and locked

 

Mine does that but very, very quietly (I can hear it but my wife cannot) - sounds like it's somewhere in the vicinity of the nearside b- or c- pillars...

It's not constant though on mine, but it is there more often than not.

I can't hear it from outside though, only inside the car.

 

Only beep I've heard like that is then the trunk hatch doesn't want to close/open because something is in the way. Do you keep your key fob in your pocket and something is pressing on the trunk open button?

 

Never heard that high pitched tone before. Any 3rd party accessories in your car? Did someone hide an Apple Tag under your seat?

 

Only car seats installed
The wife made it go away today. Moved the car seat around and fidgeted on the rear window buttons. No idea what triggers it and if it will come back 🤷‍♂️

 

Yes I can here it through the door when the car is turned of and locked

Never heard that high pitched tone before. Any 3rd party accessories in your car? Did someone hide an Apple Tag under your seat?

yeah, my exact thought.
it seems something not from "the car".
and if you hear that even with the car off it's even more suspicious.
could you trace more precisely where it comes from?