When the No. 3 went through the template station of inspection on Friday, not only did the rear deck lid not fit but officials also noticed bondo on the lid, where it appeared the putty had been used to alter its shape.
NASCAR inspectors immediately seized the rear deck lid and plan to take a closer look at it back at its research and development center in Concord, N.C.
NASCAR announced a new policy earlier this season in which as part of its focus on inspection procedures, it will assess all penalties for illegal parts at the track during the course of the weekend.
The example cited at the time was that if a car is unloaded with an illegal part, it would automatically be assessed an L1 penalty.
L1 penalties typically include a 10-40 point deduction, a suspension from 1 to 3 races and a fine up to $75,000.
Why the penalty has not been already assessed by Saturday was not made clear by NASCAR officials. It could still be assessed following the Cup race on Sunday or may be announced later next week.