On very stubborn spots that vinegar/water cannot remove, I'll use a light polish such as SSR1 or Optimum with the PC. It clears them up quickly. But that's assuming you have a PC.

If not, try the vinegar/water...or the rainX if it works.

 

I heard just buffer and some cleaner or even polish will get those water sports off. My mom has some serrious spotting on her mercedes windshield. I need to try some thing real soon.

 

I'm telling ya... Rain-X FTMFW.

 

Why would rain X remove hard water spots where some Polishes have a hard time or vinegar.

Just doesnt make any sense to me. All it does is make water bead, it shouldnt have any cleaners in it. IF Anything it can probably protect it from future spotting but the one on the windshield....

 

I think it just hides the water spots if anything. Rain-X is like wax for windshields

 

word. It smooths the surface out, kinda like a wax (as stated), and the protective shit in it would fill in the nasty water spots, and smooth it out, making them disappear/be less noticable/not visible..

dude, I'm really speaking out my ass on this one, but when I bought my truck, it had water spots out of this world, and I said "**** it" and threw some rain-x on it, cause it was already like 10 at night, and I didn't care to get them out anymore, and they disappeared. Just speaking from experience. It's not like it could hurt anything to try and alternative method either. I'm guessing it would basically act like a glaze for the windshield.