Does ceramic coating stop paint from fading or oxidizing in the sun?

It can slow UV-related degradation, but it does not stop it. Automotive clear coats already contain UV absorbers, and some coatings add further UV resistance, yet a thin coating cannot permanently block sunlight. Paint that is already oxidized or has failing clear coat will not be restored by a coating; it needs polishing or repainting first. Parking in shade or under cover, regular washing and maintaining the coating still matter for cars that live outdoors.