Another, easier technique that will probably satisfy you without the multi-step polishing process is by using a Sonus green or orange DAS pad with Optimum Poli-seal, which for many is the best one-step product on the market today. I hear great things and when my next order comes up, this stuff will definitely be on my list! Optimum Poli-seal is a light polish, sealant, and cleaner all in one product. I think this product alone will make you happy. Naturally, I would prefer doing the compound first and then this stuff, then some more P21S if you want. Here's a link:
http://autogeek.net/32ozoppo.html