I tried it out on the deck lid today. It seemed to work fine, the paint is nice and smooth.
I found out I have too much sap on the car though. Clay or the mitt won't take off old large hardened sap spots of course, I have to use alcohol first.
I'll use it on the rest of the car to check it out some more, but I might like the clay better. When you are using the clay, you can feel when the paint is smooth, as you use it, the mitt you can't.
I used the mitt like the clay, I kept both, and the paint, saturated in the detail spray. Then with the mitt, you flip it over and wipe it off, then you buff it off with a dry soft towel.
I usually put a real coat of wax on after the process.