NASCAR has decided not to penalise any of the teams found to have been using unapproved roof flap spacers which were identified by pre-event technical scrutineering before last weekend's races at Daytona International Speedway.

31 cars in total across the Sprint Cup and Nationwide Series teams were found to be using the affected parts, which are part of how the 'pop-up' flaps on the top of the cars operate to check speed when the car spins round and travels in the wrong direction. The flaps are used to reduce the chances of the car flipping over and barrel-rolling in the event of an accident.

16 Sprint Cup cars were found to to be using roof flap spaces which did not precisely conform to the rule book. The drivers affected were Jamie McMurray, Brad Keselowski, Marco Ambrose, Denny Hamlin, Casey Mears, Greg Biffle, Ricky Stenhouse Jr., Trevor Bayne, Joey Logano, Aric Almirola, Michael Waltrip, Martin Truex Jr. and Carl Edwards. The top three drivers in qualifying - Kyle Busch, Matt kenseth and Clint Bowyer - were also cited.

In the Nationwide Series, a further 15 cars were found to have similar infractions: Busch, Kenseth, Bayne, Brian Vickers, Travis Pastrana, Michael Annett, Cole Whitt, Jeffrey Earnhardt, Landon Cassill, Blake Koch, Mike Bliss, Reed Sorenson, Robert Richardson Jr., Jason White and Dexter Stacey were all determined to be in breach.

According to reports in the media, the issue was that the spacers being illegally machined down to reduce weight. The cars were allowed to compete in their respective events once the commandeered parts were replaced with authorised equivalents, but NASCAR was expected to hand down fines and points deductions in its usual post-weekend penalties announcement.

With so many cases to look into, the decision didn't come on Tuesday afternoon as is usually the case and was finally issued on Wednesday instead - with the surprise conclusion that no one would be penalised after all.

"We examined this from every aspect we possibly could and determined that there would be no penalties involved," said Robin Pemberton, NASCAR vice president of competition.

"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," he continued.

"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."

As a result, the statement from the NASCAR series organisers confirmed that it will not assess penalties to the teams that had to change out the spacers that support the hinge bar of the car's roof flaps last week at Daytona.

NASCAR usually takes a very harsh stance over unauthorised parts of modifications being used, and with some of the teams cited including those who have already been in trouble with the series already in 2013 including Matt Kenseth, Brad Keselowski and Joey Logano where crew chiefs are still under probation, many pundits expected some potentially championship-affecting sanctions.

Shepherd to set new record for oldest Cup driver

This weekend's Camping World RV Sales 301 race at New Hampshire Motor Speedway in Loudon could see a new record set for the oldest man to ever race in a NASCAR Sprint Cup Series event.

71-year-old Morgan Shepherd is due to race in the #52 Brian Keselowski Motorsports Toyota: with 43 cars entered in the race there shouldn't be an issue with the car failing to qualify, so assuming that Shepherd takes his place on the starting grid on Sunday he will break the current record held by Jim Fitzgerald who competed in a Cup race in 1987 aged 65 years, 6 months and 22 days.

"This is truly a milestone, a great opportunity and I want to thank all who are involved to help make this happen," said Shepherd on Tuesday in a statement issued by the team. "It will be good to be back for such a historical day, and I love the New Hampshire Speedway."

Shepherd currently competes part-time in the Nationwide Series and made his Cup d?but in 1970, going on to claim four wins of which three came at Atlanta. He made his most recent Sprint Cup start at age 64 on September 17 2006, also at New Hampshire. He wound up 42nd in the 43-car field, retiring after 61 laps with overheating trouble.