The sealants I've used in the past are Colinite 845 and Wolfgang SiO2 Paint Sealant, Griots Ceramic 3 in 1 Sealant, Turtle Wax Hybrids Solution Ceramic Spray Coating (its a sealant), and long...long ago, Klasse Sealant Glaze.
With any of those, once you apply them, let them set for the...