Oxidation is what happens when you paint on your car or the gel-coat on your RV (fiberglass) becomes sun-dried, faded, or sunburned.

Pollution and other industrial fallout that comes from factories, auto and other exhaust and train rail-dust in the air settling on your car or other vehicle helps oxidation occur.

Overspray is what happens when someone spray-paints a building and it floats through the air and settles on your car.