In the normal course of driving, particles like brake dust, soot and other contaminants embed themselves in your paint and dull the shine. Professional detailers use a clay bar to remove these things. What they don't want you to know is that you too can use this trick at home.
Wash your vehicle. This should be done out of direct sunlight to avoid water spotting. Wash one section at a time and then rinse before moving to another section. Use a detergent designed for car washing, and, starting at the top of the vehicle, wash the entire surface top to bottom, front to back. Do not wash in a circular motion, which will cause very fine scratches to be more visible in the light. Washing in a front-to-back motion decreases the effect of the tiny scratches caused by washing, and results in a better shine.
Prepare the clay bar by kneading it until it is pliable, and then flattening it out. Spray a liberal amount of lubricant to a 3-by-3-foot section of the car, and slide the flattened bar in a back-and-forth, overlapping motion over the section. This will require little or no pressure to pick up the contaminants embedded in the paint. Fold the clay in on itself, and knead it frequently to keep a clean surface, and avoid scratches caused by particles sticking in the clay. Add lubricant as needed to prevent the clay from sticking to the paint. When the section is clean, remove the residue with a clean, soft towel, and move to the next section. Repeat the process, section by section, until the entire surface has been covered.
Finish the process by waxing the car to restore the shine, and remove any leftover residue. Remember to use a front-to-back motion to reduce the appearance of tiny surface scratches, and work in small sections to reduce the effort needed to remove the wax.
