Playing the guessing game Who Am I? is a great way to show everyone what they have in common. Think of someone that you and your fellow passengers all know: a family member, friend or neighbor, or maybe a fictional or historical character. Then give clues about the person’s identity by revealing his or her hair color, gender and other distinguishing physical characteristics. Or allow each person in the car to ask only "yes" or "no" questions about the identity of your secret person. Keep giving clues until someone figures out the identity of the individual you have in mind.
This is a variation of the ever-popular Twenty Questions, where the only clue players start out with is whether you are thinking of something "animal, vegetable or mineral" or a "person, place or thing." The players must ask questions that you can only answer "yes" or "no" to determine who or what you are thinking about. The goal is to guess the answer in 20 questions or less.