I have had good results recently with Big White Hi-Temp Paste Wax. Put in on thin by hand or smooth pad at low rpm with a random orbit machine. Let dry to a haze, hand wipe off with a clean cloth. Buff with a finishing pad at higher rpm.

As with painting, surface prep before waxing is critical for best results. Remove hard water stains (ehite viniger usually works), polish with an ultrafine compound like 3m Finesse-it II (white color). Be careful of the new 3M ultrafine compound for cars that is blue in color, it can stain white gel coat if left on the surface more than a few seconds.