As of 2015, the rarest 1937 coupe is a Buick drop-head model with a body by the Carlton Carriage Company of London, England. The British call it a Commonwealth Buick. There is one automobile in England and one in the United States, which James Tadley of Sheffield, Massachusetts, owns.
Carlton created the bodies for about six 1937 Buicks. England's 1937 Carlton Buick coupe is in the Atwell-Wilson Museum near London. James Tadley, a retired teacher and rare vehicle collector, purchased his coupe when he saw it in Maine in 1995. The vehicle is a black convertible with an aluminum body coated with lead, a three-position top and a brown English leather interior. As of April 2010, when Hemmings Classic Car published an article about the vehicle and its owner, the coupe showed 18,410 miles on its odometer.