You have more problems with mottling when the paint is a SS you are spraying, regardless of whether you intend to CC or not. If you know ahead you want to CC, then buy the right product. Buy the BC. Even though I even said to add some clear to the last coat and then another clear on top of SS . . that is more of a last resort. SS has a lot of thickness, when used with clear really ups the overall thickness. It's not the best way. So get a BC if you plan to clear, you will also have less problem with mottling.
I have a question related to single stage paint and buffing. I am planning to paint an area of a panel but not the entire panel with Single Stage light silver metallic acrylic enamel. Is this possible with SS paint on SS paint? And if I use the tactic mentioned in this thread where clear is added to the final coat, can this be buffed to smooth out the finish or am I going to end up with a noticeable result?
Your problem will be losing the edge of the new paint into the old. With the correct blending solvents and technique it probably can be done but you will most likely have to extend the blend to the edges of the panel at which time you will ask yourself why didn't I just spray the whole panel?