Mark, not sure if you have ever tried this (and there are probably similar products out there). Last cruise we went to in the '49, John sprayed
Rain X on the windshield. I was real surprised how well it worked. Although, we didn't have a heavy rain.
He tried some on our other vehicle last week (when we did have rain). Seems it works better when you are going faster than 30 mph.
It was nice with the '49 tho ... not having to turn the wipers on and off.
I saw on the Rain X website they have other info about blades and stuff. Not sure if that will help.
Peggy