This week on Car Talk, Erin from CA shares an impromptu course in chemistry in exchange for the proper way to drive a stick shift. Will she learn anything about cars, because Tom and Ray have no shot at chemistry! Katherine crashed into her boss's car. Can she secretly repair his BMW, or is a pink slip in her future? And what is that smell in Kartik's car? Grab some smelling salts for this week's educational hour of Car Talk.