There are a few different ways to go about this. The first, and most common way is to use a polishing compound. This will remove the swirl marks and leave a smooth surface for the ceramic coating to be applied to. The second way is to use a machine polisher. This will remove the swirl marks and any other imperfections on the paint surface, leaving a perfect surface for the ceramic coating to be applied to. The third way is to wet sand the paint surface. This will remove the swirl marks and any other imperfections on the paint surface, leaving a perfect surface for the ceramic coating to be applied to.