Environmental factors affecting corrosion
Humidity
The accumulation of sand, mud and water on the underbody of the vehicle can accelerate the corrosion process. Wet floor coverings will not dry completely if left in the vehicle, so they should be removed to allow them to dry and prevent corrosion from forming on the floor.
Relative humidity
Corrosion is accelerated in regions where relative humidity is high, especially when the temperature remains above freezing, in the presence of air pollution, and where road salt is used.
Temperature
High temperatures accelerate corrosion of parts that are not well ventilated.
Air pollution
Industrial pollution, salt in the air in coastal regions, and heavy use of road salt accelerate the corrosion process. Road salt also accelerates the breakdown of painted surfaces.
Test yourself
A quick Nissan Altima quiz: every answer comes with an explanation and a link to the manual page.