DRS is not available for the first two laps of a race or the first two laps after a safety car or red-flag restart. It is also deactivated in the rain if the circuit is deemed "wet" by race ...
A wheel nut from the right front flew off Buescher’s car, sending him crashing hard ... had to step in and fix it up. It sent the race under a red flag while the NASCAR crew got down to business ...