Whenever it's the least bit humid out - humid I've been getting a fine coating of not quite dusty but more like light smokey looking film all over the inside of my windows when using any form of vents. I drag my finger across the window and it's obvious theres a fine build up of stuff there. Is there some sort of filter issues I'm having here which is gunking up my vents causing this to happen?

 

don't know what you have, i'm guessing you are refering to a 5th gen. If you have never changed your cabin fliter, go for it. I've seen some pictures of how nasty those things are even after a couple years.