W110 - What is supposed to go in this hole to the right of the wiper hole?

[unobtain]

https://i.imgur.com/GfthWrG.jpeg

Just curious what goes in this hole, looked like something rubber but it was too mutilated to tell if it was just a regular plug or not. The hole just leads to behind the fresh air flap thru a short direct passage.

[Idle]

Did the car originally have an AC? Back then all air conditioners were aftermarket and installed at the dealers. It was necessary to cut holes into the area to let the hoses pass through into the interior. If the correct size hole saw was not available then a large punch would do.

Drain holes in the floor would also just be punched out and then filled out by pushing the unit drain hoses through.