Barra is the first woman not only to lead GM, but the first woman heading any of the Big Three. In fact, she's the first woman to head any global automaker. Car Talk's Jim Motavalli interviewed her, prior to the announcement.
Maurice is loving the great mileage he's getting in his Chevy Volt. He wonders if he can improve things further if he reduces weight by keeping the gas tank almost empty. Tom and Ray think this might technically improve mileage, but by such a small amount that it's not worth the risk. Risks include: annoying friends and spouses, ending up out of gas and out of charge, naked, fleeing from a pack of hungry wolves.
Tom and Ray get a letter from John, from the department of armchair economics. While driving around, he started wondering whether the brake in his Toyota Sienna was the same part as the brake in the Toyota Corolla ahead of him at the light. Tom and Ray explain why it makes sense for auto manufacturers to use lots of shared parts.