Car shampoo, mainly for the exterior of your car, is designed to clean dirt and grease from the car paintwork and help to keep the car look sparkling clean all year round. The filmy feel of the shampoo will help to keep small dirt particles and even abrasive sponges or rags from scratching the paint's surface. High quality car shampoos that are sold in the market today have the necessary chemicals that will not scratch or leave marks when washing.