Whats that on dash

[Aparat]

Hi everyone.

On my previous and current GTI, I noticed a perfect rectangle shape with round edges on the dash above the glovebox.
Can't be a coincidence that it is the same shape in exactly the same location on 2 cars. It cant be a stain or anything because I must have tried everything on it.

Any ideas?
https://drive.google.com/drive/folders/1dNWOifFueiiXWDsODwC28QX7L2-5eIY3?usp=sharing

[Watts]

Could it be a thinner area where the passenger airbag comes out?

[Aparat]

Could it be a thinner area where the passenger airbag comes out?

Of course. Why have I never thought about it 

[Watts]

Could it be a thinner area where the passenger airbag comes out?

Of course. Why have I never thought about it