This week on Car Talk, Hans recalls fleeing from Germany during World War II in a car powered by woodchips, but he's never been able to figure out exactly how it worked. So who better than two car experts with MIT degrees to figure this out? Well, maybe anyone would be better in this case. Tom and Ray will likely do better helping David figure out how a three-pound bag of Hershey Kisses disappeared from his Civic overnight, and why his car now smells of melted chocolate. Elsewhere, Victoria's Mom needs to trade in her Corvette after surgery, so Victoria's wondering what car's right for a hip Mom with a new hip; Aaron's windshield wipers are stuck in a salute position; and, is Mary-Ellen wearing out her brakes parking in "The Gulch" every day? A box of doughnuts is riding on the answer, so this is serious business. All this and lots more, this week, on Car Talk.