Swirlmarks
I gues you did not go to a "touch-less" car wash, those, or most car washes use recycled water. I lived in Chicago, and the salt comes in by bargeload, there is alot of sand in that low cost stuf. Those rags or brushes probably caused it, there are polishes that get rid of swirls. I have had good luck with a small "ranom orbit" polisher, its great for waxing, and getting rid of water stains. PS, Chicago winters caused my rocker panels in my SL to rust, the car was not out that often.
I gues you did not go to a "touch-less" car wash, those, or most car washes use recycled water. I lived in Chicago, and the salt comes in by bargeload, there is alot of sand in that low cost stuf. Those rags or brushes probably caused it, there are polishes that get rid of swirls. I have had good luck with a small "ranom orbit" polisher, its great for waxing, and getting rid of water stains. PS, Chicago winters caused my rocker panels in my SL to rust, the car was not out that often.