How do you top up a ceramic coating?

Some ceramic coating manufacturers have a top-up product that we can apply, which will add ceramic to your coating. You can do this once a year, every few years, or when the ceramic coating is nearing the end of the manufacturer's warranty. 

Thus far, most of these products are to be applied by an accredited outlet approximately once a year, and in some cases is tied to the warranty, essentially tying the customer into an annual service. We don't think this is necessary, and not all of them do this, thankfully, but it is worth reading the small print.