The 1929 Duesenberg J/SJ Convertible Coupe stands as one of the most magnificent expressions of American luxury and engineering from the Classic Era. Powered by Duesenberg’s legendary 420-cu-in straight-eight—producing 265 horsepower in J form and an astonishing 320 horsepower when supercharged as the SJ—it was the most powerful production automobile in the world at the time. Built on a massive, exquisitely engineered chassis and typically bodied by elite coachbuilders such as Murphy or Derham, the Convertible Coupe combined breathtaking performance with hand-crafted elegance.