I was skeptical if the ceramic coating made sense. After claybaring my 2017, 2 1/2 years ago and then applying the Groits Ceramic coating, the paint is amazing. Still smooth as (use your own analogy), water rolls off, and nothing sticks to it. Truck only has 96k miles on it, but looks great. They recommend redoing it alternating years but I might do it next year. Maybe.
Could have taken it out to do “professionally” but if I do it at least I know there were no shortcuts taken.
I recently did the claybar and ceramic on my 67 Sunbeam Alpine’s 30+ year old base coat/clear coat paint (admittedly never been outside overnight) and it looks great. Glassy.
I also use the ceramic glass treatment on the Tacoma and my 2 Alpines, and ceramic chrome coating on the Alpines.