Mercedes-Benz has sold a number of automobiles with the "420" model name.
The Mercedes-Benz W126 is a series of S-Class automobiles manufactured by Mercedes-Benz between 1979 and 1992. The W126 was the second generation to officially bear the 'S' designation, an abbreviation for the German Sonderklasse or "special class." It introduced many Mercedes-Benz safety innovations, including the first seatbelt pretensioners.
The W126's twelve-year production run between 1979 and 1991 was the longest of any S-Class generation since the first "S" designated top-class models were built in the mid-1950s.