Washing your vehicle after a snow storm is something we HIHGLY recommend here at Good’s Auto Service. This is in large part due to the salt/sand mixture that is applied to the roads to help melt ice. As the vehicle is driven over this mixture, salt gets stuck to the underside of the vehicle. This includes the frame, undercarriage, suspension system, brake system, exhaust system; you get the idea. Anything under the vehicle is liable to salt residue. If left untouched, this salt mixture will begin to have a chemical reaction with the surface it is clinging to, which accelerates the rusting process. In other words, one of the best ways to help prevent or slow rust is to clean the entire vehicle after a snow storm. Not only the exterior, but the underbody and brakes as well. Many automatic car washes now have an undercarriage cleaning option, but if you are doing it by hand, we recommend spraying underneath the vehicle as well. It may be several weeks in a row that this is required, as salt stays on the roads for a decent amount of time after it is applied. But in doing this, it will help prevent rust build-up under your vehicle and hopefully extend the life of it as well.