Sole-surviving 1948 Alfa Romeo 6C 2500 Competizione Berlinetta tops Bonhams Quail Lodge sale 1948 Alfa Romeo 6C 2500 Competizione Berlinetta. Photos courtesy Bonhams Auctions. Following its 1947 Mille Miglia victory, Alfa Romeo understood its aging 8C 2900 B Berlinetta would soon be outpaced...