Hi Brian.. I read your PM and so here I am in the Mad Scientist Boiler for the first time ever (I think).
Probably half as many people have thought about doing this as there are people who have tried to figure out how to use permanent magnets to create perpetual motion --> millions.
The only way I know how to give perspective to what you and millions of others have considered doing (diverting ice, sleet, snow, rain, dirt, dust, bugs, etc. away from a windshield with a reinforced slip stream) is to give example experiments of how to test your theory at home.
As an example, If your reinforced slip stream shooting upwards over your windshield is 6 inches thick it would have less than about 1/100th of a second to almost completely reverse the direction and velocity of and/or melt the incoming ice.
Experiments:
Try to use a standard hair dryer with both blower and heat on 'high' to do either one of these two things at the same angle these things would be hitting the slip stream over your windshield:
1. Melt a small spot of frost on your refrigerators freezer inside wall in less than 1/100th of a second.
2. Reverse the direction of a drop of water from your shower head (just before it hits the tub) back upwards in less than 1/100th of a second.
Even if you had a high powered super heated leaf blower you wouldn't be able to accomplish either one of these tasks in less than the 1/100th of a second your slip stream would have to do the job at the incoming 'angle' it has to work with -- not even close.
If you have a leaf blower handy the next time it rains, use it underneath an umbrella and try to keep the rain off even a small portion of the windshield of any parked car. The physics of the problem will become obvious. At 60 mph, the problem becomes 60 times harder to solve.
You're thinking is outside the box and my advise is to never stop doing that.