United States, Nov. 6 -- GM continues its strong performance to lead the way in customer satisfaction as its portfolio of brands scored notable year-over-year improvements in an annual study analyzing the new-vehicle purchase experience in the U.S.The 2025 J.D. Power U.S. Sales Satisfaction Index Study found that Chevrolet, GMC, Buick and Cadillac were among the top performers when it comes to buyer satisfaction - based on the delivery process, dealer personnel, deal negotiation, paperwork completion, dealership facility, and dealership website. More than 32,600 customers were surveyed in this industry-wide study.Buick emerged as the standout brand, claiming the No. 1 spot in the Mass Market category and ranking 6th overall in the SSI Index...