I used a product for cleaning Ceran glass-topped stoves to remove the
water spots the sprinkler left on my kitchen window.
It was made for glass and is non-abrasive.

 

steal wool

 

steel wool grade 0000, and 3m rubbing compound. 1 hour.. glass looks like new. total cost is under 3$, and available at any small hardware store.

I lived on the beach for a year with nothing between the ocean and my car... saltspray galore... i went away for a week once and when i got back my car had a visible layer of salt on it. So trust me, i know about water spots.

 

I've got water stains on my paint, I've used the Meguire Clay Kit, ICE Wax, Scratch Off etc.. and nothing some one hel me ...

 

^rotary buffer works best

 

i have the same problem. posted this last summer https://www.rx8club.com/rx-8-discussion-3/spotted-paint-181610/

just took out the car yesterday from winter storage. still gotta fix these spots.