does slaming the rear door (upper side) affect the door in the long run?

or i should use the closing botton all the time?

 

I would guess that it would have no effect. The cars are built so solid.
I always use the button though.

 

Some of the other MFG door lifting system could be damaged by manual operation. My dealer says that you can do it either way. They did not suggest you hit the button to make it close and THEN force it to close faster.