Generally speaking, when we talk about wet sanding an buffing in the automotive environment, we are looking to get the absolutely best shine out of the paint finish on a car or truck. We are looking to get a true show car finish. To help with this I have the diagram below which shows a surface that is not perfectly flat vs one that is. This is NOT to scale, but it is representative of the surface of a car after it has been painted. (Click on Continue reading to for more information and some impressive photos that show this process.)