Zaino is the absolute best to keep the cars finish looking good. But you car aquires a static charge right when you start moving, Zaino is notorious for this. So dirt and stuff very easily adhere to the surface. Zaino makes a finish enhancer called Z6, that reduces the static charge on the surface, HUGE HUGE difference!!
I do a quick wipe down of the whole car (panels, windows, rims, etc) after I wash it. Finish looks great for quite a while.
Hope that helps.
-Sanj