I have the first two parts of meguiar's 3 step, but i replaced the wax with NXT tech wax, which freakin ROCKS. I also recently got somec claybar, but i couldn't get it to work like i assumed it would. Maybe I was doin it wrong? I donno, but if you just have a good wax like NXT you wont have to clean/polish (the other 2 steps) near as often. A good spray-on detailer will help extend time between waxes too.
I love my black truck, but it's a b*tch to keep clean!