Rain-X is NOT recommended on plastic! There are other defoggers out there, including spit and dishwashing liquidBare
The Irish cut a Potato in half & rub Potato juice on interior glass/plastic to fight mist. That is when they have a Potato.
The first 15-20 minutes of rain are the most dangerous, especially early in the season. During this time all the oil on the road comes up and makes it extremely slippery. Pull over and wait this out, then head out cautiously. Scott