So why in the world would I dig up an old thread, well, blame it on the search function LOL.

Even tho it was pouring the rain, I broke my old rule and took the ole Bolt out in it anyway. It still has it's original vacuum wipers which got me to pondering this very same question as the OP did back in 07, as I tooled along in the rain.
I was thinking about floating this subject out in a new thread but the search function found this most excellent thread that pretty much covered all the bases. I think I'm going to try a vacuum canister now.

Bernoulli's Principle, man you gotta love this stuff....

But this thread didn't answer the other related question that came up, what about a warm weather defroster?

Dave