If you've never clayed before, you're in for a real treat. The
Clay Magic is one of the better clays out there, and I noticed that my local AutoZone started carrying CM as well for $10. I just might pick the CM kit up just to have a spare, even though I already have two bars of Zaino clay. Most consumer clays are pretty small, and are usually good for a few applications.
Take your time and use plenty of lube. I use my car wash solution for the lube and everything comes out great. Leaves a perfectly smooth surface ready for polishing, waxing, or sealing.
Good Luck!
