DAYTONA BEACH, Fla. >> It was the finish NASCAR banked on as the genesis of its ballyhooed youth movement.Austin Dillon and Darrell Wallace Jr. finished 1-2 in the Daytona 500, a promising pair of 20-somethings behind the wheel of iconic car numbers that could excite old-school fans, yet a pair with enough social media savvy that might attract millennials to a sport in dire need of a spark.