Whoa, that is awesome, and it also fits with a previous car I owned. I had a Pontiac Grand Prix GTP that got water in the passenger side and it was from something where the windshield meets the hood. Your photos are zoomed in so far that I can't actually tell where they are on the car, lol. When you say under the windshield cowl, that's on the outside of the car right? Is it the bit thats kind of where the windshield wipers sit? Like the plastic cover at the very back of the engine bay when you open the hood?
*Edit* I found them. Well the passenger side at least. It's dark out so I just messed with some of the plastic bits, and pushed them out of the way. Didn't remove the wiper arms. I could get to the passenger side, but not enough wiggle room to get to the driver's side. Yup the one I got to was 100% blocked with leaves. Vacuumed it all out. The crazy thing is, that rubber oval that was filled with leaves looks like it serves ZERO purpose other than to get clogged. It's just a 2-3 inch long rubber drain that folds closed at the end. So water can pass through it, but not solids. I guess maybe the occasional leaf falling into the engine bay is catastrophic? lol. But years and years worth of leaves building up is just fine? Anyone when I was vacuuming it, that rubber oval popped out, and all I could think of was "Why are you here? If I threw you away it would just be the same sized hole for water to drain through." And of course when I put all the trim back, it didn't seem to fit right... everything felt a little loose... I swear, trim is my kryptonite.