Clay bars work. They remove above-surface contaminants, such as railroad dust, tree sap, industrial fallout, heavy film or tar from the road, paint overspray or transfer and various stains. These contaminants will often remain on the vehicle even after a thorough wash. By removing them, waxes can then properly bond to the surface and the paint will feel smoother and easier to wash and dry. You should clay your car when you first get it and then, every year, if your car is kept outdoors. Read more: Car Care Corner: How and why to clay bar your car | New and Used Car Reviews, Research & Automotive-Industry News & LeftLaneNews
Try Nanoskin, save time AND money. Nanoskin works just as well as clay bar, in literally 1/4 of the time. I use mine as I wash and do the whole car in an hour. My first clay bar took me 11 hours. Best of all, if you drop it, you simply rinse it off and it can be used dozens of times. Check it out. Nanoskin Car Care Products, nanoskin autoscrub system I only clay barred once, Nanoskin ever since.
I discovered an excellent series of informative videos on Meguiars' web site. They cover Meguiars' 5-Step process to an award-winning finish. Well worth viewing. Meguiar's 5-Step Paint Care Cycle - Updated!