After watching the latest McBain film, Grampa has a mild heart attack, and decides to tell Homer that he has a long lost brother. Homer tracks him down, and is ecstatic to learn that his brother, Herb Powell, is a successful auto industry executive in Detroit. The Simpsons drive to visit Herb, who welcomes them into his luxurious world. While taking Homer through his plant, Herb concludes that his brother has a better grasp of the American public’s tastes than his own engineering team, and puts Homer in charge of designing a new car. The engineers try to fend Homer off, but Herb insists that they listen to his brother. Homer designs a monstrous car with an enormous sticker price, destroying his brother’s company and bankrupting Herb. But, driving back to Springfield Homer is pleased to learn that Bart liked his car.