When I removed the cover and took it out of the garage a few weeks ago, I noticed that there was a hand-sized stain in the centre of the bonnet that does not appear to have been coated. When the surface of the vehicle starts to show signs of a worn coating, they need to be removed - so you can reapply a fresh coating. You can overlay the existing coating if that is easier for you or perhaps redo the entire roof section. Most professional detailers swear that using a polishing compound and orbital polishers is the best way to remove a newer tile.
However, tile removal also depends on your comfort level and experience with medium to advanced paint correction techniques. Most professional detailers will take a gradual approach to removing tile with cutting compounds. A ceramic coating will provide better protection than a sealer or wax, while improving gloss and keeping your car cleaner for longer. So, when sprayed onto a ceramic coated surface, it fills in small imperfections caused by abrasion to restore shine and reduce surface energy so that liquids can build up again.
Physical abrasion will wear it away, such as brushing, polishing, any aggressive cleaning with towels or unsuitable materials, and can damage the coating. Infusing quartz or ceramic into the paint increases the slip of the coating and improves resistance to chemical etching. I was new to coatings and wanted to see how they worked, so I opted for an affordable 18 month to 2 year coating. As you can see, the dulling effect is due to the coating wearing away in certain sections, creating an uneven surface that scatters light.
At this point in its life, the coating is likely to be very thin and relatively easy to remove. When the vehicle is completely dry, use an IPA spray or ceramic coating cleaner for final preparation before applying the new coating. In fact, our DIY nano-coating is considered by many automotive enthusiasts to be the easiest and most durable coating - which compares to several professional grade ceramic coatings.