clay bar. its awesome. use it lightly like a bubblegum erason on paper. once its start malforming and getting dirty just fold it in upon its self or pull off the dirty bits. easy on paint and its fast. i dont think there is anything better. i like zaino's clay bar. tried another one that i cant remember the company and it didnt work as well... kinda reminds me of hard tires vs soft tires. more traction with the zaino one but less longevity
i used to have a fab one. i'll see if i can dig it up. and no, no prep work, wash the car and get off as much as possible, dry completely, then work the magic stick
well what i do is i wash the car really good with dishwashing liquid. the dish washing liquid strips the paint, then i go to town with the clay bar oh & i get the clay bar at advance