You can get to it by removing the glove box & setting the vent control to recirc. There's a plastic grid in front of the opening, but you can stick your fingers in there or make a tool out of something like a coat hanger.
When I had low air flow I dug in there to find a mouse had made a nest in the 'squirrel cage' (guess it was now a 'mouse cage'!
) out of the paper towels I keep in the glove box to check oil etc. *Goes to check oil...* "Dang I
know I put a paper towel in there!!"
I was able to clear it out with my fingers... & the mouse met his demise in a trap 2 days later.
They just can't resist peanut butter!
Hth,
Fuzz