Clay removes bugs, tree sap, paint over spray, light tar, and other surface contaminants. They are actually tiny particles of bare metal that become embedded into the surface of automobiles and cause serious damage when left untreated. Rail dust is produced from the friction of the rail wheels on the rail road track. Brake dust is produced during the friction of braking. Brake pads are currently made of metal particles and During braking metal on metal friction disburses metal shavings onto the finish of vehicles.
Industrial fallout is actually another term for pollution .
There is no vehicle that can escape this contamination . These contaminant give the finish a rough and gritty feeling to the finish, you can feel them by rubbing the palm of your hand over the finish. Clay bar safely and easily removes them with out scratching the finish.