I had the unfortunate situation of parking at a hotel near Spokane, WA this past week which had temperatures roasting at nearly 110 degrees for several days (record heatwave). The hotel sprinklers got my car over night which then baked hard into the black paint the next day.
It was several days before I could get home and wash my car and discover the water spots wouldn't come out!
At first I tried a mixture of 50% white vinegar and water (saw this on multiple YouTube videos), which didn't do anything at all. I next tried the vinegar straight up, again, totally nothing. Next, I tried buffing the paint with Meguiar's Ultimate Compound, still nothing. The only thing that appeared to work is Meguiar's Water Spot Remover on a speed setting of about 5 to 6 on my Porter Cable. I followed up with Meguiar's Ultimate Polish. The water spots finally came out! but I was surprised by all the hype on the internet about white vinegar which didn't seem to work.
Has anyone else experienced this? What worked for you and what didn't?