This week on Car Talk, is back-seat driving genetic? Apparently so for Liz in Massachusetts, who's picked up the nagging habit from her Mom. Making matters worse, Liz's husband's poor navigation skills make him a prime target. Can Tom and Ray break this cycle of rolled eyes and loud sighs? Elsewhere, Jay did a little backyard maintenance on his Honda and saw his gas mileage drop by 30 percent; Ivan's suffering from an epidemic of flat tires, accompanied by odd circular abrasions; and Alexandria's car doesn't like starting on warm days. Also, why Tommy is #1 on the Must Bite list among the dogs of Unadillia, New York. All this and lots more, this week on Car Talk.