Yes, it's true: in the 1950s, people really thought we would have nuclear-powered cars. In fact, even Ford thought so. The year was 1958 and nuclear power was all the rage. Ford reckoned that uranium reactors would eventually be small enough to fit into a car, so it built the Nucleon as a proposal. The idea was to swap reactors if you were running low - something you'd need to every 5000 miles. The idea naturally went into mushroom-cloud oblivion before even leaving the drawing board.