Vehicle paint is exposed to many environmental hazards - water spots, paint over-spray,  tree sap, bird droppings, rail dust, bugs, etc., etc.,. One of the techniques now used by professional detailers and body shops, is to "clay the vehicle". This involves using a clay bar to "polish" the surface, in turn removing these imperfections. Clay comes in several "grades", which relate to its agrressiveness/abrasiveness, or ability/speed at removing imperfections. There are abrasives in clay, so the safest approach in my opinion, is to use the mild grade (less abrasives). The approach is to start with a clean vehicle - next step is to mist the surface with a non-silicone lubricant - Race Glaze® Gloss Highlighter works very well for this. Once the contaminated surface has been lubricated, rub the clay in a back and forth motion, like sanding a piece of wood - the clay should "float" or "hyrdoplane" over the surface. To achieve this, it is very important to use a liberal amount of lubricant. Depending on the contaminant, it may be necessary to clay the surface more than once. It is better to be conserative, than to over do it. Keep in mind, that every time you clay the surface, you are removing a very small amount of the paint/clear film. One technique I was shown several years ago, was to place a piece of cellophane (like a cigarette pack wrapper) between your fingers and the dry paint surface, and slide this over the surface. Its interesting how you can feel defects with the cellophane, that you cannot feel with your finger alone. Another interesting thing to do, is to take a close look at your paint - pick up a "printer's loop" (type of magnifying glass), or an inexpensive portable microscope (child's models available at many toy stores - some have a battery powered light). In any event, if you use clay, be sure to use a clean surface for each application. If you don't, chances are that eventually you will find out the hard way, that you picked up a contaminant that is behaving like a piece of sand in the clay, and you will be "sanding" the surface. Either "fold in" the last surface used, or cut/break it off. The same is true if you happen to drop the clay - be very sure you expose a clean surface before using the clay. When you are finished using the clay, return it to an airtight container/bag, to prevent it from drying out. After claying your vehicle, it is very important to wash off any contaminant residue.  My recommendation for this job, is Race Glaze® L.A.S. Wash - excellent cleaning ability, Ph balanced, biodegradeable, and very free rinsing. The next step is to protect the paint - following directions, apply a coat of Race Glaze® Polish & Sealant. It leaves a crystal clear proective coating, that stands up extremely well to contaminants, and lasts on average for 4-6 months. If you have any questions on any of our products, call us at 1-800-Mr-Shine (1-800-677-4463),                      or e-mail us: mr-shine@mr-shine.com.