in the United States. In 1988, the plant was closed. In the early 1980s, the manufacturing division and the sales division were merged, and Volkswagen of America moved to Troy, Michigan, as a result, settling in Auburn Hills, Michigan, in 1991 (). 1990s uncertainties Volkswagen of America's sales hit rock bottom in 1993, with fewer than 50,000 cars sold that year. Sales began to recover the following year with the introduction of the third generation of the Golf and Jetta. By the end of the decade, thanks to effective advertising and the launch of more competitive new products, including the New Beetle in 1998, the VW brand was back on firmer ground. Volkswagen of America went on to sell 355,648 cars in 2001, its best year since 1973. 2000s In the 2000s sales tapered off somewhat due to competition, quality issues and delays in product introductions, and VW's U.S. sales for 2005 totaled 224,195 – a reduction of about 37 percent from four years earlier. New models for the 2006 and 2007 model years, such as the Passat, Rabbit, and GTI resulted in a sales growth of 4.9% for 2006 with sales of 235,140 vehicles. Profitability still remained an issue, though; Volkswagen of America had not turned a profit for its parent company since 2002. In January 2007, Volkswagen of America president Adrian Hallmark publicly stated that he planned to get the subsidiary back to profitability in two to three years. He hoped to introduce new models for North America, and develop new marketing to encompass the whole brand as well as individual cars. Stefan Jacoby soon replaced him, and Volkswagen of America continued to look at new products to add to its lineup. In the meantime, a new advertising agency, Crispin Porter + Bogusky, helped rejuvenate VW's presence in the U.S. as well. Its ads for the fifth-generation GTI have sparked interest in the brand, not seen since the launch of the New Beetle, and ads for the fifth-generation Golf/Rabbit hatchback translated into initial strong sales for that model. Due to new air pollution rules promulgated by the United States Environmental Protection Agency (USEPA), the diesel powered VWs with TDI-PD technology could no longer be produced after December 31, 2006. For the 2009 model year, VW introduced a new generation of diesels, based on common rail technology. These would meet air pollution standards in all 50 states. The first