Just to play the devil's advocate here, while I did PPF on the front of the car the rest has simply been manually cleaned and waxed (no ceramic or exotic wax products or coatings) in the summer, and run through a touchless car wash occasionally this winter so the undercarriage gets a regular 'hows your father' to clean off road salts and the like.
Paint looks immaculate, shines brilliantly, and beads water easily. I know ceramic is a popular choice, but I'm not sure if my paint could look any better than it does, to be honest.