Most people wash their cars to make it look and shine real good. It is very important to wash your car for other reasons. Dirt and grime does more damage to a person's car than people realize. Contaminants such as tar from roads to asphalt will cause what some call car cancer and will eat away at your paint. The clear coat wears down first.
The under carriage of the car does not get as much attention when it comes to cleaning. A car suffers more damage during the winter months because of salt and sand that city crews lay down to melt the snow and ice. Most people do not fully wash their cars during this time of year. The salt advances the cancer rate on the chassis and lower parts of the body.
General motors products see more rust/cancer damage on the lower body of the car than Fords or Dodge products. The cars body will last longer if you thoroughly wash your car regularly.
