Nowadays automobile companies pay great respect to Aerodynamics curve of Cars. Aerodynamic curve of cars reduces air resistance in a moving care and help for both smooth drive and fuel efficiency.
But car companies ignore presence of charge particles like NO, NO2, CO and nascent O and also Hot air still touching the surface like bullet and causing corrosion. As time passes, shine of your cars is removed.
On the Road, Cars are moving behind the other automobiles. Charged particles like NO, NO2, CO and O are emitted from Exhaust of other automobiles and also due to hot atmosphere, hot airs flow on the road.
Car moving is constantly torching against these charged particles and hot air and subjected to corrosion.
Similar to Automobiles, Boats, Submarine, linear are subjected to constant corrosive Salt water of Sea. No matter, anti corrosive paints are applied, still at nano level corrosion do take place. In order to avoid this and safeguard the life of Boat, additional suicide metal is attached which is more electropositive and itself get corroded. Thus, protecting the surface of Boat and increasing durability.
Automobiles may use these small metal piece made of zinc or other electropositive metal, which is corroded and surface shine of Automobile is protected.