White hose in b-pillar... What is it for?

I was doing nonsense back there and it just came out of the hole, wasn't yanking or being too foolish, is it just ventilation? Here are pics.
This is passenger side behind lower seatbelt.

 

Do you have a sunroof? Could it be a sunroof drain hose?

 

This is my guess as well. Drain hose for the sunroof pan

 

Plug it up....turn the hose on your sunroof and see if it floods.

I am fulla ideas. None of them are any good.

 

Lol. i do have a sunroof, makes sense, i didnt want to take off the other side panel, ill put it back in the hole and hope for the best .

Back to rewiring and MLV....