Originally Posted by FP
1) you should clay at least once or twice per year.
2) Take a baggie, put your hand in it, and pass it over your hood or any other part of the car body. If it's not smooth, and you feel the imperfections, it's time to clay.
Watch these links for the best details on clay bar use.
http://www.adamspolishes.com/t-Videos_DVD5_16.aspx
http://www.adamspolishes.com/t-Videos_DVD5_17.aspx