Below the windshield, is this plastic in there, or hardened crud?

Behind my apt. I have to park outside (without a covering carport). Below the windshield of my beloved Prius C there’s a kind of “louver” area about a foot long with slots that I presume are intended to allow runoff water from the windshield to drain down to the pavement.
I’ve been saving $ by cleaning up bird droppings & dirty spots myself. But tiny leaf fragments & assorted crud was clogging up the slots (especially for a few inches at each end of the louver), so I used a tweezers to pick out as much of the crud as I could.
As I push the tweezers down through the slots, it looks as if there may be a piece of plastic (to guide water) for a few inches at each end.
Am I right about that? Or have I hit really hardened crud?