Hard Water Stains
Around 4 days ago my car was caught in my neighbors sprinklers. Unfortunately the water dried and my car was left with some hard water marks. Today I washed the car and tried to remove the marks, but unfortunately even after washing, and then treating the area with P21 Gloss Enhancing Paintwork Cleanser, the marks remained. I even tried claying the area, but the marks remain. I finally tried Meguiars Scratch X 2.0. After 2 separate attempts, it partially removed the stains but a few still remain.
I'm at a loss here. What other products should I try treating the area with?
Past: 1999 Techno Violet Metallic M3
Present: 2011 135i 6MT