If you have water spots and other stains on your car windows I suggest this.

Purchase a clay bar,Maguire's or Mother's will do, follow the instructions as if you were doing the paint work on your car. BUT- instead of using a soap based lubricant, use the STONER GLASS CLEANER as the wetting agent. After finishing this process follow up with the above suggested STONER'S GLASS CLEANER and newspaper. I prefer week old VERY dry newspaper. IMPORTANT!! Ink must be VERY DRY!
When dry, just rinse off the clay bar with glass cleaner and save it in a plastic zip lock bag.
I do this 3 to 4 times a year on my year round cars and twice a season on my show cars. You can also do this process to the inside glass front and back, as long as it is NOT TINTED.

I have used this method on over a hundred cars and EVERY customer EVERY time freaks out on how clear their windshield is.
Good luck fell free to ask more questions

 

Stoners + crumpled newspaper and then finish up with microfiber cloth. It looks like you could reach right through the glass.

 

My biggest challenge is always the insides of the windshield and rear window.

I start with a quality glass cleaner like Mothers, or I hear Stoners is good. I spray it on a microfiber mitt so I can easily use the back of my hand if necessary. Sometimes I'll stand with the door open to reach the side corners.

Probably the key to glass cleaning -- and this may depend on the cleaner -- is to wipe/clean with a wet side of the cloth and before it dries, flip to the other side of the cloth (or a fresh cloth) for a streak-free clean.

I only trust plush microfibers or waffle-weaves. I only use paper towels to initially remove the crud if necessary. Some like newspapers, but inks aren't what they used to be and I've heard too many stories about grit in the papers (like a stray bit of sand) scratching the glass.

 

I clayed my windows yesterday per INTRUDER's instructions and am happy w/ the results. Optically clear under any lighting condition. Thanks!