That Hole Where Windshield Wiper Spindle Protrudes--What's Below It?

[PowrRam]

I park under a crabapple tree. The tree sheds leaves, twigs, crabapples, crabapple stems, etc. Every couple of weeks I open the hood and scoop out a bunch of debris that collects up near the base of the windshield. Today I noticed there is a lot of this crap settling near the windshield wiper spindle area as there is a sort of a recessed area there. I noticed there is a half-hearted attempt at a foam gasket to seal off the wiper spindle to the environment. I say half-hearted attempt because there is a noticeable gap around the gasket. It's obvious that debris is falling into this gap and disappearing somewhere below.

My question is this--What's below the hole that the windshield wiper spindle protrudes from? In other words, where does this debris go that gets past the gasket and into this hole?

 

[GTyankee]

Under the hood on the passenger side
There is an inlet to your heating cooling system, ( climate control )
You definitely don't want anything except air going into that inlet

 

[PowrRam]

Most of the debris enters the hole where the driver's side wiper spindle is located. But I suppose some gets into the passenger's wiper spindle area. What happens the debris that gets into the heating/cooling area? Can the debris be easily removed?

Anybody know were the debris on the driver's side ends up going?