Well, first of all, what kind of cloth are you using to wash the car with? It's gotta be 100% cotton cloth, or microfiber towels work too. I just cut a small piece off my large bath-size towels and use that to wash with, plus a seperate one for the wheels. Secondly, spend the money and get the Z7. Maintenance is very important in the Zaino system, and Z7 and Z6 are the integral components for that.
Also, some people have expressed less-than-desirable results with the SMR, particularly finding that after washing the car, the swirls are back. I'm not all that familiar with SMR, but if it is a glaze, then it just fills in the swirls and is mostly removed with the next wash. What you need is a
polish that will actually remove the swirls, not just fill them in. I highly recommend 3M's new Perfect-It III machine glaze. You will definitely need a buffer for it though.
All this said though, I find that no matter how careful I am, I occassionally still end up with a couple of swirls in the paint after a wash. That just gives me an excuse for another coat of Zaino.
peace
Mike