Number 4,
I got curious with my 98 and decided to look. I have the same situation, mine has been sitting for a while and had a massive build up of junk in there.
A) Remove wiper arms. Little 90 deg clip on windshield side has to be pulled out after the wiper arm is held up.
B) Rocker the wiper arm back and forth and it comes right off.
C) Single Phillips head screw in the center of the cowl panels gets removed.
D) Left side cowl panel comes up, Long flat blade screw driver works best. (Work slowly to avoid breaking clips and tabs). 3 tabs in front and 1 in the back. Windshield washer hose needs worked off as well.
E) Same thing again for the right side cowl panel.
F) Look up under the right side cowl plate and you should see what looks to me like a 4" X 6" oval stack that's about 2" tall. My guess is that it would be the fresh air inlet.
Almost seems like you could put metal window screen over the top and wrap in it down around the sides and secure with a hose clamp or large zip tie.
Not much room to work with in there so removal of the right side hood hinge assembly may give you extra room to work with.