A fellow autopian (kleraudio) and myself went to properautocare today to catch up with the guys and talk about some products (and of course spend a fortune). They are a big seller of both s100 and P21S. Apparently for a long time most retailers could not sell both, but that changed a few years ago, when the products went through their respective changes. According to them, before 2004 the products were basically the same product. Then "major" changes went into both products and they were separated so to speak. He explained that any tubs purchased after the change (mid 04), are completely different. He said you can look at the wax, feel the texture, and see the difference. He also said that he believes that most people could tell a difference if they were applied side by side. Different products for different type of applications. All in all, the guys they are great and really explained a lot to us about Menzerna and Blackfire and P21S and Eiman Fabrik.