From Jayski which got it from Motorsport.com:
NASCAR is planning to use next month's Monster Energy NASCAR All-Star Race as a test of the Xfinity Series aero package debuted last season at Indianapolis Motor Speedway, Motorsport.com has learned.
The aero package used in the Xfinity Series last season included a restrictor-plate, but even more importantly, aero ducts on the front spoilers and a taller rear spoiler.
For the Xfinity Series package, the aero ducts - which move air out of the front wheel wells and create a larger wake - increased the draft envelope by approximately 25 percent, which generally allowed the trailing car to race closer to the leading car.
The restrictor-plates slowed the field down and helped prevent the leading car from running away from the field.
The package received generally positive reviews following last year's Xfinity race at Indy. The race produced an event record 16 lead changes across an event-record eight different drivers.
Interested to see how this plays out. The Xfinity race at Indianapolis last year was fantastic. I'm not sure how well it's gonna work at Charlotte.