For many Americans the process of negotiating for a car is a symbol of adulthood. The act ofbuying a car comes double glazed with meaning. We want both a great deal for ourselves and a heroic tale about how much we saved. The great deal and the good story are both part of what we call the "subjective value" in the transaction.In reality, buying a car is one of the worst investments you can make. As soon as you pull the car out of the lot its value plummets—there’s no such thing as owning a new car.In my first few weeks on the showroom floor I would brag to potential customers that Acura had the highest ROI (Return On Investment) on the market. Basically that got me nowhere. People cared more about the premium Milano leather seats. Why? Because most people view buying a car as a personal decision not a business decision. This kind of thinking can lead to impulsive purchases, lack of research, and rushed negotiations. FAIL.