Feb. 19, 2010 -- The drivers of NASCAR's Sprint Cup Series will start their engines Sunday at the 53rd running of the Daytona 500 and five-time defending champion Jimmie Johnson is on a quest for an unprecedented sixth-consecutive series title. But the weekend will also be marked by somber tributes. Sunday's race in Daytona Beach, Fla., will be the 10-year anniversary of Dale Earnhardt Sr.'s death on that same track.