Cowl Vents

[unplugged]

I took notes when taking the car apart on everything not "obvious" on how it would go back together.
8 years later there are a lot more items that are no longer obvious then there were when I took it apart.

One of these is what holds the cowl vents in place. Perhaps related there are 3 large holes (16mm +/-)in a curved plate below the center of the vent. The plate appears to function to keep water from entering the air intake when raining but the holes would appear to defeat this purpose. The holes have a slight bent edge that look like something large may thread into them.

Are these what hold the plastic vent piece in place ?
What about the edges?

Thanks
Dave

[grittracing]

the holes are for 3 large rubber adjustment screws to how the vents in-place