Claybar is a popular car cleaning product that can be used to clean black cars. The product is available in a variety of different concentrations and can be used on both the exterior and interior of the car. The instructions for using Claybar are very simple and easy to follow. First, add the desired amount of Claybar to a small bowl or container. Next, wet your hands and apply the Claybar to the surface of the car. Be sure to use as much or as little as you need to cover the entire surface of the car. Finally, wait 10-15 minutes for the Claybar to dry completely.