A vehicle can be covered in dirt and grime, meaning the surface needs to be cleaned. When you wash your vehicle, you move the dirt and grime from the surface of the vehicle via the washmitt. This is done via mechanical cleaning. Although you reduce the risk of surface imperfection via the correct way of washing, you are still not risk-free. Any form of mechanical cleaning will always have a small risk. If the surface is more dirty, the risk becomes bigger. Pre-washing removes much of the dirt and grime without the need for mechanical cleaning. Unfortunately, pre-washing isn’t strong enough to completely clean the surface, so some mechanical washing is still needed.