P21S is the name of the wax. It is also labeled as S100. It's the same wax just different names. The only local places I know of that carry P21S/S100 are Harley Davidson stores. If you don't have a Harley store near you, you can order a jar from
www.properautocare.com
Here's what P21S/S100 looks like:
http://www.properautocare.com/p21spastewax.html
EDIT: I just noticed the price listed on Proper Auto Care....$31.95

They used to sell it for $14.95!! I guess word got out about how good it is...maybe the Harley stores still sell it fo $14.95?