After picking up the car from repair shop and cleaning throughout inside...you don't see those when entering or exiting the car as usual.

 

I can't tell what I'm looking at here. What part of the car is this?

 

My guess would be from the seatbelt buckle? If it doesn't retracts all the way up & when you closed the door,
the door edge will smack against the buckle & the frame. I get that often on my truck.

 

Interesting guess. That said it leaves me baffled as I don't recall ever running into this problem not a single time ever since I've owned the car (3 years). I've never ever closed the door with the seatbelt dangling, it has always come up efficiently anyway. Also the rubber gasket all around shows no marks whatsoever in the same area, it should show some marks if something like a turnbuckle had been smacked in-between. And there are many dents not just one. Just totally confused at this point...

 

Agree, seat belt buckle.

 

Seems like its in the plastic or rubber, kinda hard to tell from the pics. If so, either case, use a heat gun, not too hot, and pass it along the area. That should puff out the indications.