I have used the G2 paint on numerous vehicles. As noted above, take the wheels off so you can do all four, as the two-part paint will set up in a few hours.
Clean the calibers with the cleaner supplied with the paint kit, tape off areas and paint away. By the time you paint all four once, it is dry enough to start all over again. Minimum 2 coats, 3 better.
Time consuming but worth it if you like your calibers painted, some do, some don't. I can also attest to great customer service. I ordered a special color which costs twice as much and got the wrong color. Contacted G2, they asked for picture as I used the paint, since once mixed, no turning back. Sent them a picture, they agreed not ordered color and sent me new paint kit.