Wayne has no trouble starting his 2002 Nissan Maxima. But the car isn't similarly obliging for his wife, as he told the answering machine that's set up for prospective guests on NPR's popular call-in radio show "Car Talk."

Ty, meanwhile, left a message wanting to know whether it was normal for his 2008 Toyota Celera convertible to surge forward at 35 miles per hour. Unbidden, the hazard lights and headlights on Kristen's 1997 Acura keep turning on. And when Michael drives his 1982 Ford Bronco XLT Lariat on the highway at any...