Zymol is overpriced and only ok. I've tried some of their most expensive waxes and was disappointed. Meguairs Gold is decent but lacks the longevity and depth that I like. Try the 1Z (einszett) polishes and Glanz Wax. Good pricing and excellent quality. I've only been trying 1Z for about 8 months now, but I get more excited each time I use it. Prep your paint with one of the polishes (either the red can or green can) and then top with the Glanz. Awesome results and much better than the two you're asking about. More bang for your buck for sure. I get mine from Detailers Paradise (
www.detailersparadise.com), but I know there are a few other places online where you can get it too.
Polish is a preparation step for wax and is ESSENTIAL to your paint care process. Many people overlook this step and don't realize its value. As stated above already, it cleans up the paint and adds shine. The wax adds additional shine and depth, as well as protection. Most polishes don't offer any protection. Although jackasssi already explained this, I thought I'd support what he already said. Definitely true!