This is gonna sound like some kind of ad, but please bear with me - I have two tips that you may find useful, and I need to get this typed before I sober up.....

Tip #1.
When it rains lightly, or the car has dew on it, my wipers seem to work fine but always leave a nasty film - I just assumed old windshields get that way. I tried windex, with zero result.
So as we drive I mentioned it to my daughter and she said "you know what would get that off?.....Mr. Clean Magic Eraser™ " (yes, I DID think it strange that she actually pronounced the trademark sign.)
I fished one out of the box under the sink and went to work on the passenger side - it was hard going and the sponge soon fell into little pieces, but after a brief consult with a 'sponge expert', I wetted the foam with some soapy water and tried again.
The result was as close to a friggin miracle as I've seen. Film absolutely destroyed and glass polished to a high shine, wipers no longer drag and it's as smooth....as glass!
Will be adding some to my car wash/detailing kit.

Tip #2.
These little foam pads are 'expensive'.
Miracle workers they may be, but even at the local TryAndSave they are over $2 each, and last about half a windshield!
Google informs me they are made of BASF/Procter & Gamble melamine foam, but further GoogleFu told me that various websites sell these tiny foam blocks for under $20 per 100.
The ones I bought cost 17.8 cents apiece, shipping included. (See, it's not an ad.)
Well obviously the Stealthster has no use for 100 of these, (unless my 90 hamsters need pillows) but I did find that putting ten in a ziplock bag and giving a bag to each of my friends (so 3 bags, total) made me some kind of hero..."do you know how MUCH these cost?"

Yes, actually I do.

 

i have some film that makes driving in the rain a difficult task. ill make sure to give this a shot, thanks!

 

To this day under the right conditions I can still read the EPA mpg rating for my car on the passenger side of my windshield.

 

This is interesting, going to try it out on the beater. It doesn't leave fine scratches that create halos at night, does it?