Corrosion warranty coverage includes naturally occurring corrosion during a set period of time. This is offered through some manufacturers and maybe by a local dealership as an add-on warranty. Corrosion coverage usually covers the corrosion or rust that can occur on the surface (or paint) of your vehicle after the paint and protective layers have been compromised from an accident or natural exposure. Natural exposure is more likely to occur in desert or coastal environments where there is more particulates in the air. Left untreated, corrosion and rust can create a significant problem and work it’s way into the mechanical elements of your vehicle.