well the vingear and windex worked really well on the side windows, ok on the windsheild...might have to try some of the stronger products above cuz the back window is really stubborn.

I tried using Stoners invisible glass and also vinegar but the water marks were still there... I'm using a microfiber towel. Am I doing any thing wrong?

How about hard water stains on paint and wheels? :(

You should be able to easily polish those out. I use a mild polish (Griot's) and my six inch orbital buffer.

I had a problem with water stains when I bought my 350Z in FL. The only stuff that took it off was from Home Depot. Don't remember the name but is used to remove corrosive water stain from concrete and house sliding window. It comes in a red gallon, however you have to use gloves and have a hose to rinse the car so it doesn't get to the rubber or the paint of the car.

That was the only thing that worked, due becuase the stains came from the untreated water that they used in Florida for the water sprinkler system. I don't know if that is your case.

No idea, it's so hard to get rid of! Do car detailers offer this type of service?

My dad used to use coke(acola) to get rid of the crud on the windshield. then clean with water. Kinda the same idea as vinegar I guess.

I would caution you about the Barkeepers Friend "Non Abrasive" Cleanser, used it occassionally on my other car's windshield (after a friend recommended it) and it put very fine swirls all over glass. You could only see it at night (from the inside) and was quite annoying to look through when oncoming cars headlights reflected/refracted the light.

This site has some great products. Glass wax with high speed polishing pad will do it.. Autopia Car Care Products - Car Detailing Supplies, Car Wax, Car Polishers, Auto Detailing

try baking soda with that vinegar, if that doesnt work, then use some glass polish and what ever you do, do not use the rough side of a sponge! use microfiber or an applicator pad

I just got the water stains off the back glass this weekend. Tried several things, different glass cleaners, etc..

Finally I tried some meguires fine cut polishing compound/cleaner. I had some already, and I'd read that it would work. It took 10 minutes and cleaned it right up. It's perfect now.

Where can I buy that? Does it require any machine?

advanced auto, or anywhere that sells meguires products. It's just a real fine cut polishing compound/cleaner for removing swirl marks out of paint.

No machine required, I just used one of those terry cloth covered polishing sponges. You could use a rag.

Is this the one? Amazon.com: Meguiar's M0216 Mirror Glaze Fine-Cut Cleaner - 16 oz Bottle: Automotive

I hope it works, tired of buying things that don't work :( (Someone recommended using Lime Away (the stuff used for toilets to get rid of hard water stains) Bought it, tried and still didn't get rid of the stains on my window.

Yes, that's it. I gaurentee you it will work.