I have been using Zaino since i got my PT cruiser in 2000. I have yet to find a superior product. A great bonus is that it is really easy to apply, and it does not leave the white wax residue. I clayed my smart and applied 3 coats of Z2. The nice thing about Zaino is that you can apply it to plastic, so i used it on the roof also. As always, i love the results. Although a bottle of Z2 costs 15 bucks, i can get a minimum of 16 applications out of it, and that is on cars bigger than my smart. Plus, it lasts longer than anythnig i have ever used. Even on my cars that a keep outside, the water still beads after several months. I have tried most all of the other major products. A lot of them are pretty good (mothers and meguirs are good products). I just think the Zaino is better, based on my experience using all the products.