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NASCAR announced Thursday morning that they have assessed a major penalty to Brad Keselowski and the RFK Racing No. 6 team after discovering that the team had modified a single-source supplied part for the Next Gen car. The infraction was discovered after NASCAR had taken Keselowski's No. 6 back to their Research & Development Center following the Cup Series race at Atlanta Motor Speedway earlier in March.

Keselowski has been docked 100 driver points and 10 playoff points, and RFK Racing has been docked 100 owner points. Crew chief Matt McCall has been suspended for the next four Cup Series races and also been fined $100,000.

The penalties to Keselowski and his race team fall under Sections 14.1 of the NASCAR rulebook, with the infraction rising to the level of an L2 penalty. RFK Racing is the first team to be penalized under a stricter penalty system introduced by NASCAR this year, which outlined severe sanctions for modifying parts on the Next Gen car supplied by a single source.

RFK Racing announced their intentions to appeal the penalty, and their appeal hearing took place on April 7. The National Motorsports Appeals Panel subsequently ruled that the penalties against the team would stand. RFK Racing had the option of filing a final appeal to the National Motorsports Final Appeals Officer, but indicated in a statement that they would decline to do so.

"Although we are disappointed in the outcome of the appeal hearing, we are advocates of the process NASCAR has set forth and appreciate the opportunity to make our voice heard in the matter," read the statement. "With that in mind, we do not intend to pursue this further and our focus remains on our upcoming races."

RFK Racing's penalty for illegally modifying a Next Gen part comes several weeks after the team avoided penalty for doing something similar in the leadup to the Daytona 500. NASCAR had found evidence that RFK Racing had reamed their wheels after confiscating them, but the adjustments had been permitted under the NASCAR rules.

The 100-point penalty to Keselowski now drops him from 16th in the Cup Series points standings all the way to 35th. Keselowski finished 12th at Atlanta.