In the 1970s, Chrysler’s TV commercials played up its vehicles’ "rich Corinthian leather.” That meaningless phrase, dreamed up by marketers and cooed by actor Ricardo Montalban, became emblematic of what defined a luxury vehicle.

Fifty years later, those words have been replaced by elements that are creating a new concept of automotive luxury: recycled PET bottles, coffee grounds and tree fiber.

"The definition of a premium automobile is changing,” said Rudiger Recknagel, Audi’s chief environmental officer. "It’s now who’s using the best materials with the least environmental impact.”