The 1963 Datsun 1900 Sprint concept car. People who know a lot more about cars that I do have explained to me why it isn't practical for auto manufacturers to actually put concept cars into production, but I always forget the reasons because the beauty of the concept cars overwhelms me. This car is 45 years old, yet if it were on the road today, people would go ape for it.
UPDATE: Ruth points out this was actually a Prince. Pre-Datsun. Ok, Ruth! Thanks!