Should I apply a second layer of ceramic coating, and when?

Some coatings are designed for layering, and a second layer can improve uniformity and fill in any areas missed during the first application. The timing between layers matters: many products specify a window after the first layer flashes or partly cures, and applying too early or too late can affect bonding. Follow the manufacturer's layering instructions rather than assuming more layers automatically multiply durability, because that depends on the product.