I'd echo Zaino and Autopia as everyone else has.
Though you'll find a lot of other great sealants other than Zaino. If you think cigar buying addiction is bad, wait until you get sealant/wax/polish/car care stuff addiction. Woo-Wee.
Other popular sealants are: Blackfire Wet Diamond, Four Star Ultimate Paint Protection, Wolfgang Deep Gloss, Menzerna Power Lock to name a few. The latest craze is the Wipe On, Walk Away sealants such as Optimum Opti-Seal, Zaino Clear-Seal, Ultima Paint Guard Plus, etc. Literally spread it on evenly and let it dry. No buffing off.
But with anything, preparation for your last step product (known as "LSP" on Autopia) is a KEY ingredient to a nice shiny/slick paint surface.