Brent,
Any way you slice it, getting caught in a down pour ain't pretty.
I keep a towel in the car with me to deal with what you are talking about. Wipers wiping on the outside and me wiping on the inside has kept me alive long enough to drive through the storm. The alternative is to stop on the side of the highway (dangerous) and take a shower. or if lucky enough, pull under a bridge. (also dangerous)
Steve