Since this thread has popped up again, I would like to add my speculation on the electric car. The first automobile driven in Manhattan was an electric buggy purchased by Diamond Jim Brady in 1895 (he didn't drive it himself, he was chauffeured). Everything Diamond Jim Brady did was big news; it was front-page news in New York and it would have been known throughout the country.

Of course, Diamond Jim had nothing to do with a murder in St. Louis but, since the line is not essential to the song, and the time is about right, maybe with the Brady connection, his electric car found its way into the song.

Just a thought.