People do strange, dangerous things to entertain themselves and others. Real lawn darts were once sold as children’s toys. Almost as soon as automobiles became somewhat practical, people were figuring out dangerous and fun things to do with them.
The earliest automobiles were typically rich folks’ novelties, which may explain why, in 1902, Joshua Crane, Jr., a polo enthusiast active with the Dedham Polo Club of Boston, decided to put on an exhibition polo match wherein Mobile Runabouts replaced horses.
That it might not have been the safest endeavor can be seen from a surviving photograph of the match catching one of the drivers/mallet men doing a header into the ground, about to be run over by his own steed.