55-57 Chevy Door Lock Retainer for a 2-Door Hardtop, Convertible, 4-Door Sedan and 4-Door Wagon. You can insure that your new door locks will stay in place for good by installing them with new door lock retainers. Our door lock retainers are made of heat treated spring steel for the strongest spring pressure, and are cad plated for rust and corrosion protection. With these exact reproductions youll be certain your door locks will stay securely in place. Made in the USA.