ABOVE LAS VEGAS — Almost 5,000 feet above Las Vegas Motor Speedway, Xfinity Series driver Matt Jaskol is hanging onto the side of a helicopter that’s circling the facility. If he were an ordinary driver, he’d be on the ground going through driver introductions, then preparing for the start of the Xfinity race. But Jaskol is no ordinary driver. Instead, 30 minutes before the green flag, he’s outside the helicopter with a parachute strapped to him, about to make one of the most elaborate entrances a driver has ever made prior to a NASCAR race.