Dean's driving the impala, or "baby" as he likes to call her, while Sam is spouting off directions to him. Your in the backseat, still in surprise because just hours earlier the brothers, after killing a spirit targeting you, figured out your their younger half-sibling. So now your joining them. Not that you kind of had a choice, since they want to be able to protect you like they wanted to protect Adam. They did at least promise to teach you about hunting, at least? That's a plus, right?