Z8 weekly for the vehicles I detail with Zaino. Maybe a coat of Z2-Pro every couple of months. Of course, if I need to do a little QD'ing, I grab Z6 for these vehicles.
Mothers Reflections Spray Wax weekly on the other vehicles, and Mothers Reflections Top Coat and/or Mothers California Gold Carnauba once a month or so. My QD of choice on these vehicles is FK425.