MONTEREY, Calif. — Mercedes-Benz dealerships ranked the highest in the newly released 2012 Pied Piper Prospect Satisfaction Index, which measured dealership treatment of car-shoppers. Study rankings by brand were determined by the Pied Piper PSI process, which ties "mystery shopping" measurement and scoring to industry sales success.

Acura, Infiniti and Lexus dealerships finished in a tie for second. Overall auto industry performance improvement was widespread, with 24 of 34 auto brands improving PSI performance from 2011 to 2012. Industry-wide improvement led to a new highest recorded industry average PSI score of 105.

Mercedes-Benz dealerships led all brands in 10 of the 60 different sales activities measured by PSI, such as the salesperson introducing him or herself, providing a thorough test drive and focusing attention on three to five memorable features or benefits. Twenty-two different brands led at least one sales process category. For example, Cadillac salespeople were the most likely to mention the availability of different financing options, Nissan salespeople were most likely to ask for the sale, and Toyota dealerships were most likely to give compelling reasons to buy from their specific dealership.

Industry improvement was widespread, with 78 percent of the individual sales process factors improving on average. However, despite the industry improvement, performance by individual brands and individual dealerships still varied considerably.

"This year's record high PSI results show that today's dealership employees work harder than ever to be helpful to car shoppers," said Fran O'Hagan, president and CEO of Pied Piper Management Company LLC. "A dealership's success depends upon many factors that are very difficult for dealerships to change. In contrast, dealership sales effectiveness is simple to measure and simple to change."

The 2012 Pied Piper PSI U.S. Auto Industry Study was conducted between July 2011 and June 2012, using 4,419 hired anonymous "mystery shoppers" at dealerships located throughout the U.S. For more information, go to .