BEIJING, Feb. 17 -- Racing fans will have many questions when the NASCAR season kicks off today with the Daytona 500 race, but auto makers only wonder whether the sport will retain its popularity and keep driving vehicle sales. The millions in NASCAR nation are wondering whether fan favorite Dale Earnhardt Jr can find happiness with his new deep-pocketed Hendrick Motorsports team, whether rival and teammate Jimmie Johnson can successfully defend his Sprint Cup Series title and what impact the bigger, boxier "Car of Tomorrow" design being used in every race this year will have. For those financially linked to the National Association for Stock Car Auto Racing's success, however, last year's lower television ratings, and declining attendance at many of the venues in the 36-race season has raised the question of whether the racing circuit's popularity has peaked. For now, General Motors Corp, Ford Motor Co, Chrysler LLC and Toyota Motor Corp still love the sport's potential, increasing or maintaining NASCAR-related budgets that top US$100 million in some cases. "I'm not really quite sure if NASCAR has peaked, or if this is just an adjustment period," said Mike Accavitti, director of Chrysler's Dodge brand and head of motor sports. "In the meanwhile, even where it's at, there are still 75 (million) to 80 million NASCAR fans out there ... and being in the automobile business, this is exactly the types of folks we want to be talking to," he added. While many major US sports saw TV ratings slip, NASCAR was hurt more than other leagues last year by spiking gasoline prices, since a large number of fans drive long distances to attend the weekend-long events. Studies by the various auto makers show that fans are more likely to buy sponsor cars and pickup trucks - and that, in the end, is what matters most.