The two brands whose sales are down the most this year according to Ward's data, rank the highest in J.D. Power and Associates’ latest Customer Service Index Study.

The top-ranked brand, Ford Motor Co.’s Jaguar Div., finished 13 points higher than last year’s top performer, despite its 181 U.S. dealerships averaging 6.7 sales per month through June – a 27.4% decline from last year.

Jaguar, which finished fourth last year, significantly improved its service quality and service initiation this year, according to the survey.

General Motor Corp.’s Buick brand ranks second in the study, although sales are down 27.9% this year.

Toyota Motor Corp.’s Lexus, which topped the study in 2006, tied for third with Cadillac.

According to the study, customers who show up for service without setting an appointment are more satisfied than customers that make appointments.

“Customers who plan ahead and make appointments to have their vehicles serviced expect that the dealership will prioritize their vehicles,” Tom Gauer, senior director of automotive retail research at J.D. Power and Associates, says. “However, when customers with appointments see that drop-in customers are receiving the same attention and priority, their satisfaction drops.”

The study also shows that 62% of customers visit dealership service departments for maintenance rather than repairs.

The 2007 CSI Study measures the satisfaction of customers visiting the dealer service department for maintenance or repairsduring the first three years of ownership. The study is based on responses gathered between January and April from 84,495 owners and lessees of ’04 to ’06 model-year vehicles.

J.D. Power measures six categories in the study: service initiation, service advisor, in-dealership experience, service delivery, service quality and user-friendly service.