A smooth surface is key to making any polish or wax work properly. Since it's a good idea to put a good coat of wax on your Corvette after winter, it is vital to “clay bar” your car as well. You need a special piece of clay designed for automotive use. You rub the paint with the clay and a lubricant to pick up the dirt and pollen and grit that is left behind after a wash. This will create a smooth surface and ensure the polish and wax will be maximized.