So when my son drove the M, it was parked outside 24/7. We used to live in a development that had lawn Nazis who ran the community sprinkler system constantly. His car was sprayed every day and left to dry in the sun most days. Now there are hard water deposits on the passenger windows and rear glass that I can't seem to get rid of. I tried a polishing compound which helped a little and even tried a solution of 75% vinegar & 25% water. The spots really show up from inside the car when the sun hits the windows. Any thoughts on how to finally get rid of them?

Might be unorthodox, but maybe try a clay bar kit (either synthetic or regular)? Just make sure the window is wet with soap, etc.

You could try lemon juice (not the bottled stuff), but I think that might not work on spots that are almost baked in. Mothers and Meguiar's make hard water spot removers. I've not used these myself so I can't comment on their effectiveness, but both should be readily available from local auto parts stores and Walmart.

Replace side window glass & tint the back one? Hehe.

I'm in for ideas as well, but I'm curious what effect the water had on the paint if it affected the glass in such a manner.

I had a similar issue and found the hard waters spots were hard to remove. I had parked in a garage in Seattle for a couple of days under a sprinkler pipe that either had a slow leak or just condensation combined with the rust on the outside of the pipe made for a mess on my sunroof, roof and rear window. I ended up using a combination of a clay bar made for glass and a product for cleaning glass from Griot's Garage. The two items that I used were:

https://www.griotsgarage.com/product/gl ... rom=Search
https://www.griotsgarage.com/product/fi ... rom=Search

The clay took off most of it, except for my rear window. I ended up using the clay and the glass polish on that window to get all of the water spots off. I'm sure there are other good products out there, I drive past Griot's headquarters store 3 or 4 times a week and like to drop in. They're great because they'll take the time to show you how to use it on your own car.

EdBwoy wrote: ↑

Sun Jan 19, 2020 11:21 pm

Replace side window glass & tint the back one? Hehe.

I'm in for ideas as well, but I'm curious what effect the water had on the paint if it affected the glass in such a manner.

I can't really see the spots in the paint - the color is diamond graphite so it hides dirt and whatnot pretty well. There are spots on the chrome surrounding the windows and the trim piece that goes up the C pillar on the rear window though.