The car was part of a five-year project to create a safer vehicle following several deaths in competition, particularly the crash at the 2001 Daytona 500 that killed Dale Earnhardt.

[5] The car was introduced in the 2007 Cup Series season at the Food City 500 on March 25 and ran a partial schedule of 16 races.

[3][13] During the prior season, three drivers (Adam Petty, Kenny Irwin Jr. and Tony Roper) had perished in on-track accidents.

[16] The primary design considerations for the new car were "safety innovations, performance and competition, and cost efficiency for teams.

[21] It initially featured a detached wing, which had not been used since the Dodge Charger Daytona and Plymouth Superbird in 1970, in place of a rear spoiler.

[18][19] The radiator air intake was placed below the front bumper of the car, to reduce overheating caused by debris-clogged grilles.

[18][24][25][26] In the first two races at Bristol and Martinsville Speedway, the garages were opened one day early and the inspections took up to 10 hours so that everyone (teams, officials, etc.)

[18][24] During the CoT era, NASCAR attempted to eliminate "gray area" and ambiguity within the rule book, and frequently adjusted the rules to ensure that different car manufacturers have relatively equal cars;[18] one such instance of rule book changes against gray areas occurred after the 2008 Sprint All-Star Challenge, in which Sam Hornish, Jr. ran a car with skewed setup to finish second in the Showdown and advance to the All-Star Race,[27] as well in 2012 after Hendrick Motorsports' teams ran with skewed sway bars to win five races during the spring portion of the season.

[28] With the transition to the Generation 6 car, the claw continues to be used along with manufacturer-specific templates[24] until 2018, when both was replaced by the laser-based Optical Scanning System (OSS).

On January 15, 2010, Cup Series director John Darby informed teams that NASCAR would transition back to the spoiler, to increase downforce and prevent airborne accidents the rear wing was believed to cause.

Another major problem was that the safety foam used in the side of the car would catch fire, engulfing the driver's cockpit with smoke.

[37] Criticisms of the CoT began with its first tests, with the magazine Speedway Illustrated noting the car's poor performance in traffic (February 2006 issue).

The Winston-Salem Journal also noted extensive criticism of the project during 2006 testing, with drivers becoming more vocal by July 2007 and most fans rejecting the model, citing the falsity of many of its technical claims;[38] one angle of criticism was the differing philosophies of NASCAR officials Gary Nelson and John Darby, with Darby a particularly ardent supporter of the CoT based on a misreading of the sport's competition packages.

[41] On April 4, 2008, while in a qualifying run for the 2008 Samsung 500 at Texas Motor Speedway, Michael McDowell's right-front sway bar broke, causing him to lose control of his car and strike the wall outside of Turn 1 head-on at 185 MPH.

The car, along with the SAFER barrier on the track wall, was praised for its safety, as the speed upon impact of the crash was about 30 miles an hour more than Dale Earnhardt's fatal accident.

[5] In the 2008 Brickyard 400, the longest run under green flag conditions was 12 laps due to extreme wear on right-side tires, especially the right rear.

The lack of downforce on the car and its higher center of gravity created conditions that made it very hard on the right side tires.

[5] But the story of the new car was a phenomenon of lock-bumper superdrafts – two cars would literally lock together and push into a clear lead, with speeds up to 10 MPH faster than with a conventional draft (on numerous occasions 2-car superdrafts topped 206 MPH); this phenomenon had debuted at Talladega Superspeedway in the spring of 2008 when Denny Hamlin discovered he could push Kevin Harvick all the way around the track during practice, resulting in a lap time about a half a second faster than the rest of the field.

Dale Earnhardt Jr. and veteran drivers such as Richard Petty and David Pearson were sharply critical of this new style of racing, especially in the wake of a race-record sixteen caution flags, most of them for crashes caused when pushing cars spun out leaders; Earnhardt Jr. himself crashed during an attempt at a green-white-checker finish in the 500.

To dissuade the two-car tandem and return to pack racing, a new superspeedway package was introduced for the 2012 season, including a curved spoiler and a lower and longer rear bumper.

The tandem remained prevalent in the Nationwide Series until 2014, when pushing was prohibited after a massive crash at the end of the 2013 DRIVE4COPD 300, in which 28 spectators were injured by flying debris off of Kyle Larson's airborne car.

[47] In spite of strong criticisms of the CoT's handling characteristics and the racing styles it created, it also produced one of the most competitive periods of time in NASCAR history.

[5] Following the elimination of the CoT in 2013, NASCAR Chairman and CEO Brian France identified the model as his biggest failure as the head of the sport due to the lack of manufacturer identity.

[4][49] For 2013, NASCAR allowed manufacturers to design a brand-new body style for the COT chassis that resembled a given production car even more.

During the 2012 season, it was announced that Ford would use the Mk.V Ford Mondeo, known as the Fusion in the Americas, Toyota would continue to use the 2013 Camry, while the Holden VF Commodore, rebadged in North America as the Chevrolet Super Sport (SS), replaced the Chevrolet Impala[51] and Dodge announced they would use the Charger.

The second-tier series also utilizes different body style, primarily marketing American pony cars such as the Ford Mustang.