Soak all of your sandpaper in a bucket of water for at least an hour. Keep sandpaper wet until you are ready to use it.
Wash the car thoroughly with a chemical cleaner and hose it down with clean water.
Fill another bucket with clean water.
Wrap a piece of 1,500-grit sandpaper around a sanding block and sand the painted surface of the car in the single direction of the wind, not back and forth or in a circular motion. Dip your sandpaper in the bucket of clean water periodically, and wet down the surface of the car to keep it wet at all times. Change your water whenever it appears cloudy or dirty.
Squeegee off the water on the car once you are finished sanding the surface. The paint should have a flat, dull appearance. Re-sand any shiny spots with 2,000-grit sandpaper, moving in one direction and keeping the paper and the car's surface wet. Squeegee the car again once you are finished.
Apply a buffing compound to a wool buffing pad. Polish the surface of your car, using a buffing machine. To finish, buff the car again with a buffing machine, a foam buffing pad and more buffing compound. Continue buffing the car until the surface is as shiny as you like.