I just started using the clay bar I purchased from Zaino's. Without a doubt this is the most significant advance in paint cleaning/detailing I have ever come across. The bar is rubbed lightly over the (soapy wet) paint surface to pick up imbedded paint contaminants. It leaves behind a glassy smooth surface. Works very well on areas like the hood which seems to develop a gritty feel very quickly from environmental fallout. I'm wondering how long I can use the clay bar before it needs to be tossed. What about the danger of scratching the paint while rubbing it with a contaminated clay bar? Is the clay bar too good to be true? Has anyone found an inexpensive clay bar?