The Pebble Beach Concours d’Elegance is a long walk through automotive history, all of which could be considered “cars of tomorrow.” But there were two retrospectives that embraced the term: a line of a dozen Tucker 48s and a brightly colored lineup of the Citroen DS. According to one Tucker owner, this grouping was the largest gathered in one place since the debut of the movie in 1988, “Tucker: the Man and is Dream.” Among...