DIY Removable Window Awnings?

This post may be more appropriate under the "Wish List" section, but I wondered...
Has anyone designed and constructed lightweight, removable window awnings? Specifically, for the windows over the sleeping area of an RP180.

My wife and I spent 3 evenings over the July 4th holiday in N. C. The evenings were cool enough so that with the roof fan on and the windows at the foot and head of the bed open, we slept comfortably enough, temperature-wise.

As is the case on many southern summer evenings, with the sinking of the sun comes a shower/drizzle/drencher/deluge/gully-washer/frog-strangler...
rain.

Some of which was pulled in to a greater or lesser degree on my head and feet by the fan-induced breeze as I snoozed. Not enough to really wake me, but enough to start me to thinking, in my drowsing state, about awnings. Lightweight, removable awnings.

And rather than try to 'Reinvent the Wheel,' I suspect one (or more) of my creative fellow-PODders has had a similar experience in the past, and raced home from a campground to his/her workshop eager to put tin-snips to metal (or fiberglass, or plastic sheeting, or fire-hardened Whale-bone) in an effort to fabricate some device/devices that will allow entry of the breeze, whilst excluding raindrops.   

So, has anyone tackled this one yet?

Moseyman