Preventing pitts
The cars were made affordable. To make chrome last, steel is copper plated, then nickel plated, then chrome. The Chrysler Imperial models had good chrome that lasted.
Our cars bumpers have steel, nickel plated, then chromed. The plating was thin, and prep was not perfect, so small voids exist. Pollutants like nitric acid from exhaust, salt attack. The wax helps. Parts can be rechromed, and can end up better than ever. I favor the natural look. Pits show the car is a well kept survivor.