NASCAR declined on Wednesday to penalize the 31 cars that failed inspection in the Sprint Cup and Nationwide Series at Daytona.
NASCAR confiscated the teams' roof flaps, which are designed to keep cars on the ground during spins and wrecks at high speeds, for further inspection.
Thirty-one cars, including 16 in the Sprint Cup Series, failed inspection before Thursday's practices at Daytona International Speedway.
''Based upon our inspection and subsequent review, it was our determination that the functionality and safety aspects of the roof flaps were not compromised and the on track competition would not be impacted,'' NASCAR vice president of competition Robin Pemberton said. ''Moving forward we will work with the roof flap manufacturer and the race teams to evaluate and optimize the associated installation hardware, review the process in its totality and communicate in a timely manner to the garage area any revisions that we determine need to be made.''
The roof-flap spacers had been illegally machined down to reduce weight.
NASCAR inspectors made those Cup teams install new, unaltered roof flaps before drivers were allowed on the track for the first of two practices.
Inspectors then went to the Nationwide garage and found similar issues on 15 cars.
The Cup cars involved included all three Joe Gibbs Racing entries (Kyle Busch, Denny Hamlin and Matt Kenseth), all three Roush Fenway Racing entries (Greg Biffle, Carl Edwards and Ricky Stenhouse Jr.), all three Michael Waltrip Racing entries (Clint Bowyer, Martin Truex Jr. and Michael Waltrip) and both Roger Penske Racing entries (Joey Logano and defending series champion Brad Keselowski). Cars driven by Jamie McMurray, Trevor Bayne, Casey Mears, Marcos Ambrose and Aric Almirola also failed inspection.
Nationwide drivers busted include Bayne, Brian Vickers, Reed Sorenson and Travis Pastrana.
