"We moved down here from Fairbanks two years ago and I thought we would never need our car heater plug-ins again," wrote Thom Foote of Colbert. "People always ask us what the electrical cord hanging out of the grille of our vehicles is for. Now I'm glad we didn't get rid of them."
Had not thought about those in a while.
My dad used a plug-in when we lived on Michigan's Upper Peninsula for a couple of years. Can't remember if it connected to the dip stick or attached to a heating element elsewhere on the engine block. But everyone had them.