There are many environmental contaminants present especially in the snowy and rainy months. The most common contaminants include mud, road tar, grit, grim, salt, acid rain and industrial hazards. When your car surfaces are protected with wax or sealant, most of the contaminants are repelled creating a barrier of protection. Any contaminants that are not repelled actually stick to the wax or sealant, rather then sticking to the paint therefore it can be removed much easier than if your vehicle is not protected. It is also beneficial to your car to keep the corrosive contaminants off of the under carriage.