I have another datapoint for "machine" as a term for an automobile. In Elizabeth Enright's Melendy books, a series of children's books written about and set in the time of WWII, there is an older woman, a family friend, who loans the family her car after they move out to the country. She refers to it as the Machine (with the capital letter). I remember thinking it was a very odd thing to call a car when I was about nine. But then I also found it rather strange when the little boy of the family referred to his precious prewar metal cars, too. I kept wondering if someone had misspelled pewter.