I've given up on Meguiar's step 3 (wax). 1 and 2 (cleaner and polish) are still awesome products, but for the final protection I'm switching to Mother's California Gold.

My latest test was to apply fresh coats of both waxes to different parts of the truck before going offroading this past weekend. The parts done in Meguiar's were dirtier (the dirt stuck to the paint easier), and after a washing this morning only the Mother's wax kept the water beading. In fact, the parts waxed with Mother's barely even needed a washing, just hosing them off cleaned everything up.