Snow foam is a form of foam that you can attach though a lance to the tip of your pressure washer and allow it to create thick foam all over your vehicle, so that it looks literally like snow.
This foam is a pre-wash solution that is concentrated and takes out all the dust and dirt from the painted surface of your vehicle. A snow foam car wash goes a long way in preventing scratches from the dirt and also does not leave any swirl marks that normal washing of your car will often do. It shows the best results on paint that is dark, especially black.
This foam is similar to car shampoo, but requires proper application for it to be most effective. The foam has to be allowed to soak on the exterior until its starts dissolving and dripping to the ground.