In Pixar's Cars, which 1950s Hudson model is Doc Hudson based on?

In Pixar's Cars, Doc Hudson is based on a 1951 Hudson Hornet.

The Hudson Hornet was a real American automobile famous for its success in stock-car racing during the early 1950s. Its low profile and strong performance helped it compete effectively against larger cars. Pixar used that history as the foundation for Doc Hudson, a retired champion whose racing achievements have been hidden from the public.

Doc's fictional record of three Piston Cup championships echoes the real Hudson Hornet's racing reputation, though the film uses its own characters and competition. The model should not be confused with other Hudson vehicles such as the Commodore, Jet, or Wasp. Doc's design is one of Cars' clearest links between animated character work and real automotive history.