The most beautiful car ever designed in my humble opinion is the Citroën DS (’55-75). I had never seen one in person until recently, as I was walking down Keizersgracht in Amsterdam, and I can asure you it’s absolutely jaw-dropping. I’ve never seen one of these in the states, so thankfully I took a photo.

{From wiki:}

The Citroën DS was manufactured and marketed by the French company Citroën from 1955 to 1975. Styled by Italian sculptor and industrial designer Flaminio Bertoni and the French aeronautical engineer André Lefèbvre, the DS was known for its aerodynamic futuristic body design and innovative technology, including a hydropneumatic self-levelling suspension.