NASCAR released the Post-Event Penalty Report for Auto Club Speedway:
Monster Energy NASCAR Cup Series Auto Club Speedway
Infraction Date: 3/18/2018 (post-race inspection)
Team: #18-Kyle Busch
Violation: Sections 10.9.10.4: Tires and Wheels. Note: Lug nut(s) not properly installed.
Penalty: Crew chief (Adam Stevens) has been fined $10,000.
NASCAR XFINITY SeriesAuto Club Speedway
Infraction Date: 3/17/2018 (post-race inspection)
Team: #18-Ryan Preece
Violation: Sections 10.9.10.4: Tires and Wheels. Note: Lug nut(s) not properly installed.
Penalty: Crew chief (Eric Phillips) has been fined $5,000.
— NASCAR —