You know there's trouble in River City when Americans who could afford to buy a luxury car not long ago are opting for mainstream brands today. 'Emotional-Satisfaction Gap' Is GrowingThe latest sales trend analysis, as part of a JD Power Automotive OEM Intelligence Report, suggests the bloom is coming off the luxury car rose. –JD Power ReportWhile JD Power notes "a measurable migration," it also sees premium owners "simply choosing a different class of vehicle. For the auto industry, this sales trend represents a double-edged sword: Lincoln, Cadillac, Audi, Acura, Lexus, Infiniti, and Genesis are among the luxury brands with certain vehicles that share underpinnings with mainstream brands owned by the same parent company. In response, their product development teams need to think more about mainstream brands as rivals, which means offering gotta-have styling, technology, or performance that can't be found in common cars.