FONTANA, Calif. – Both NASCAR Cup Series teams from JTG Daugherty Racing were penalized Sunday ahead of the Auto Club 400 at Auto Club Speedway.

The No. 37 Chevrolet Camaro ZL1 1LE team of Ryan Preece and the No. 47 Chevrolet Camaro ZL1 1LE team of Ricky Stenhouse Jr. each received an L1-level penalty after their respective cars were found to be out of compliance with the NASCAR Rule Book.

Both Preece and Stenhouse’s vehicles were in violation of Section 20.20 of the NASCAR Rule Book, dealing with Assembled Vehicle Overall Rules.

The section in question notes that “parts, systems, devices, omissions or component failures cannot affect what would otherwise be the normal airflow over the body of the vehicle.”

The infractions were discovered during pre-qualifying inspection.

As a result of the rule violations, both Preece and Stenhouse were forced to forfeit their starting positions for the Auto Club 400 and will start from the rear of the field. Stenhouse had qualified 10th and Preece had posted the 20th-best lap during Saturday time trials.

Both teams will also be docked 10 driver and owner points, and crew chiefs Trent Owens (No. 37) and Brian Pattie (No. 47) have been ejected for the remainder of the Auto Club 400 per the at-track penalty provisions outlined in the NASCAR Rule Book.