Hard-Coat Automotive Undercoatings provide outstanding chip resistance and leave a smooth, clean finish. Hard coatings as their name implies, dry hard allowing them to be top coated with finishing paint which you can't do with wax, oil or asphalt based coatings. They do a decent job of corrosion protection but do not do well on surfaces that are not completely free of all rust and corrosion. They provide minimal sound deadening and don't lubricate moving parts as other coatings might.
If you are looking for a beautiful finish that is highly chip resistant, this is the coating for you.