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- State of Jefferson
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- 2017 CX-5 GT AWD+
Depends on the location. Some places are really strict about recycling that water, some not so much. Some recycle to save money, regardless.I am pretty sure they use only some of the rinse water for washing, but the rinse is clean water.
As for dirt and salt. I dont think dirt protects paint. Any dirt left in contact with paint will damage it. If that dirt remains wet without any salt, it will cause rust. Cars from the 70s with more nooks and crannies would have chunks of dirt thrown up into the wheel wells and around the fender lip. The dirt would build up, stay wet and rust. Even in non snow climates.
I think that is why most wheel arches have plastic cladding. No more lip for dirt to collect in to rust.
Paint doesn't rust. It protects the metal underneath. That's not to say it can't be damaged. Dirt damages it mechanically. UV damages it. Chemicals can damage it. Friction damages it. It even oxidizes. But it doesn't rust like metal.
Pretty much all cars are "undercoated/rust-proofed" these days, so I wonder how big an issue rust is with modern cars anyway. I personally haven't seen any since the 80s, or know anyone who's had a problem since then.
My own biggest concern is how nasty the car looks in the winter when it's not washed.