Denny, I have been using Zaino since I bought my vette.
It's great stuff, worth every penny. Stick with it.
As you probably figured out by now Z6 is just a detailer for quick cleaning of dust, etc..
Z5 polish is better on darker color cars like our Polo Green, Z2 works best on lighter cars. In either case the more coats you put on the better it looks.
Here is what I suggest.
Z18 claybar, Z1, Z5, Z7
Get some Dawn dishwashing detergent and remove all the old wax. Use the claybar with the Z7 car wash as lubricant. When you're done wash the car with the Z7 and dry it. Apply your Z1, then when that is dry apply Z5 directly over it. When you apply the Z5 don't do it in a circular motion like with normal wax. Use back and forth motions.
For normal cleaning I just use the Z7 wash and Z5.
The first application looks good but by the time you get about your 5th or 6th coat of Z5 on you really start to take notice.
great stuff