Hi, I'm new to the forum. I just got an '04 Durango. This is probably a dumb question. My windshield just above the rearview mirror has a small area that looks like a storm door window screen. What is it's purpose? Thanks...

 

To block the sun when you look in your rear view mirror if the sun is in that direction.
FF

 

also helps your rearview from direct sunlight which can cause it to become sundried and faded or cracking.