Cadillac and Audi are the most improved automobiles in terms of brand perception over the past year in the luxury sedan segment, a new survey found.

According to Kelley Blue Book Marketing Research's Brand Watch study, Cadillac improved most among the factors of driving comfort, exterior styling, interior layout/design, interior roominess and cargo/trunk space. Audi was deemed most improved when evaluating seating capacity, luxuriousness, available options and prestige brand.

The results are based on Brand Watch study data in the luxury sedan segment from the first quarter of 2007 to the first quarter of 2008.

"Both Cadillac and Audi have introduced new models and significant redesigns and, at the same time, they've ramped up their marketing efforts over the past year, moving the important needle of perception up among luxury new-car shoppers," said Jack R. Nerad, executive editorial director and executive market analyst for Kelley Blue Book and kbb.com. "The results of this Brand Watch study demonstrate how quickly consumers can change the way they perceive brands when exciting new products and marketing campaigns enter consumers’ consciousness."

Cadillac's largest increase came in exterior styling, where it improved 10 percent, while the average change for the segment was a 1 percent decrease.

Audi increased 17 percent in available options, compared to the rest of the luxury vehicle segment, which showed a 1 percent increase.

The study delves into how each manufacturer's brand equity differs across vehicle segments, compares the relative standing of each make versus competitive makes, and reveals the decision factors of new-vehicle buyers within each make and segment. Brand Watch solicits the opinions of in-market new vehicle shoppers on various attributes within each vehicle segment, such as fuel efficiency, safety, driving performance, durability/reliability, family friendliness and the "cool" factor/vehicle image.