Auto exhaust cupids. (It doesn't just mean that love is exhausting. It's a reference to auto racer Lydston Grandville "Cupid" Hornsted.) From Le Régiment, 1913.
And yet we also spotted a 14-years earlier instance of cherubs in car smoke, presumably not related to Cupid the car racer. So it's some sort of "thing." From Lustige Blätter, 1899.