well, once you figure out how to remove the water spots, using the suggestions here
in this post.
after washing the car windows use two soft towels one to wipe off the excess water
and the other to buff the rest before it dries.
ive always used rain x on my windows dispite what some poeple say about the stuff
and never had any problems, once you have it on all you do is run your hose along
the top of your window and the water just sheaths off, no drying. works for me.
good luck.