Roof flaps from 16 Sprint Cup cars failed an inspection before Thursday's practice at Daytona International Speedway.
NASCAR officials also confiscated the flaps from 15 Nationwide Series cars. The device keeps the cars grounded during crashes.
The list of Sprint Cup drivers whose cars were cited includes Kyle Busch, Matt Kenseth, Carl Edwards, Michael Waltrip and Brad Keselowski, Jamie McMurray, Casey Mears, Aric Almirola, Marcos Ambrose, Greg Biffle, Ricky Stenhouse Jr., Joey Logano, Trevor Bayne, Denny Hamlin, Clint Bowyer and Martin Truex Jr.
The problem was with illegal spaces on the hinges of the flaps. NASCAR said the teams substituted their own pacers for the approved manufacturer spacers.
"The manufacturers supply you with a kit for the spacers on the roof flaps, and these 16 cars were not in compliance," NASCAR spokesman Kerry Tharp said.
The teams were required to install compliant flaps before the violators were allowed on the track. All of the effected cars were able to eventually practice.
A.J. Allmendinger posted the fastest Sprint Cup practice time for Saturday's Coke Zero 400 at 200.218 mph, followed by Bowyer at 200.214 mph.
The Nationwide drivers with the illegal spacers were Busch, Kenseth, Bayne, Brian Vickers, Dexter Stacey, Cole Whitt, Jeffrey Earnhardt, Landon Cassill, Blake Koch, Mike Bliss, Michael Annett, Travis Pastrana, Reed Sorenson, Robert Richardson Jr. and Jason White.