Teams will not be allowed to alter side skirts
O'Donnell said it would police flared skirts "by any means possible," including use of the new pit road technology that will make its debut during Speedweeks at Daytona International Speedway. The pieces, officially known as vertical rocker panel extensions, are located along the bottom of the car's body between the front and rear tires. They help seal the area between the bottom of the car's chassis and the track surface, limiting airflow underneath the vehicle. Not all teams were flaring the pieces last season, but those that did typically would make the adjustment during an early pit stop.
NASCAR allowed the practice to continue as the season progressed, but said on several occasions it was something that would be addressed after the completion of the 2014 season. NASCAR.com