Although many misquote Montalbán as saying "rich Corinthian leather" or "fine Corinthian leather" in the commercial, he actually says that "soft Corinthian leather" is an available upholstery option for the car.
Corinthian Leather is a marketing term that does not actually indicate any particular type of leather. Furthermore, Montalbán confirmed this during an interview with David Letterman, admitting that Corinthian leather means "nothing." According to one reference, Chrysler's "Corinthian" leather was mass produced in a plant in Newark, New Jersey (not Corinth).