Bygone Auto is a term used to describe classic cars that are no longer in production. The four solutions for this crossword are DATS, REO, NASH, and EDSEL. DATS stands for the Datsun Motor Company, which was a Japanese automobile manufacturer founded in 1931 and ceased operations in 1986. REO stands for the REO Motor Car Company, an American manufacturer of automobiles, trucks, and buses that was founded in 1904 and ceased operations in 1975. NASH stands for the Nash Motors Company, an American automobile manufacturer founded in 1916 and merged with Hudson Motor Car Company in 1954. EDSEL stands for the EDSEL Motor Company, an American automobile marque that was founded in 1958 and discontinued in 1960.