Such attitudes are a far cry from the way Americans have approached their car buying in the past, researchers say. Buyers have put a high value on reliability, durability and fuel efficiency, of course, but just as important have been looks and luxury. "What are the neighbors going to think when they see the car? Is it going to impress them?" said Geoff Wardle, director of advanced mobility research at the Art Center College of Design in Pasadena, Calif., which is known for its auto design program. "When it comes to buying a car, people take leave of their senses."

For many drivers, their cars are an extension of themselves, displayed as fashion or an accessory. "You wear your car like you wear a Ralph Lauren suit," said Clotaire Rapaille, an anthropologist and psychiatrist known as the car shrink, whose company, Archetype Discoveries Worldwide, studies consumer preferences. But today some of these fashion statements -- say, a Hummer -- would land on the worst-dressed list.

Going green is climbing on the list of criteria for many consumers. Mary Conner, 52, vice president for merchandising for Gearys Beverly Hills, a jewelry and luxury gift store, has driven BMW convertibles for over 20 years. "I love the car," she said. "It's absolutely gorgeous." But last month Ms. Conner put her BMW 330Ci convertible up for sale. She decided to hold on to the car she had originally bought for her two sons: a Mini Cooper, which gets twice the mileage per gallon.