Put some Coroplast under the soft ducktail to absorb any spray through. Coated the screen pretty good and then put another layer of window screen on top of that. It's just started to rain so I'm not sure if it's gonna set or not. Guess I'll find out after I start driving...
I ended up stapling some Gorilla tape to the 2nd layer and then taping that down to the cab. I stapled the sides to the aero cap so hopefully the 2nd layer won't fly off...
As far as I can tell...there's no rain on the back window!