2006–2009 Montoya did not want to race for McLaren and preferred American-based racing; He discussed moving to
NASCAR with CGR with
Felix Sabates in June 2006. Montoya spoke with his father, who persuaded him to switch series, He informed Dennis of the news and was promptly sidelined from McLaren since he made the statement without informing the team first. Montoya was released from his McLaren contract four weeks early thanks to
DaimlerChrysler's intervention and a rumoured $5 million compensation from Ganassi. He rejected an offer to return to F1 with
Toro Rosso after telling team principal
Franz Tost that he was focused on NASCAR. Montoya began an intensive training regimen to prepare for the following season, including
Mark Martin on how to give drivers space. in his
Nextel Cup Series debut at the season-ending
2006 Ford 400. Montoya made his stock car racing debut in the
Food World 250 (part of the
ARCA Re/Max Series developmental championship) at
Talladega Superspeedway as preparation for his first full-time NASCAR season, starting second and finishing third. He made his NASCAR debut in the
Sam's Town 250 of the
Busch Series at
Memphis Motorsports Park, driving CGR's No. 42 Dodge, and competed in the final three
2006 Busch Series races. Montoya had his best Busch Series start and finish of 2006 at Memphis, starting ninth and finishing eleventh. Montoya started 29th at Homestead, but his car caught fire after
Ryan Newman hit the back of his vehicle, sending him into the barrier. and developed a rapport with his crew chief
Donnie Wingo. Montoya frustrated approaching drivers by blocking them when he was one lap down. He was outperformed by both the
Hendrick Motorsports and
Joe Gibbs Racing teams resource-wise and had difficulty handling the
Dodge Avenger model of the
Car of Tomorrow that was unbalanced when amongst packs of cars. Wingo sent Montoya onto a track early in the season in a car with understeer before modifying its setup to boost speed by allowing the rear end to swing out through corners. , where he took his second career top-ten finish Montoya qualified 36th for the season-opening
Daytona 500, finishing nineteenth following handling issues and avoiding a
multi-car accident on its final lap. Following three sub-par races, Montoya earned his first career top-five finish in the
Kobalt Tools 500 at
Atlanta Motor Speedway that March. He finished seventh in the
Samsung 500 at
Texas Motor Speedway after colliding with
Tony Stewart. Montoya started 32nd in the
Toyota/Save Mart 350 at Infineon Raceway and led the final seven laps after passing
Jamie McMurray for his first career Cup Series victory, becoming the series' first foreign-born winner since
Earl Ross in
1974. He started and finished second in the
Brickyard 400 at the
Indianapolis Motor Speedway four races later. The rest of the season yielded two top-tens at
Dover International Speedway and
Martinsville Speedway for 20th in the final
championship standings with 3,487
points. Montoya drove the No. 42 CGR Dodge in 17 Busch Series races in
2007 to gain experience on tracks where he also competed in the Cup Series. He led a race-high 43 laps in the
Telcel-Motorola Mexico 200 at the
Autódromo Hermanos Rodríguez before bumping his CGR teammate
Scott Pruett with eight laps remaining for his first NASCAR victory and become the first foreign-born NASCAR winner since
Ron Fellows in
2001. Montoya finished two more races in the top ten, at Atlanta and Talladega, and his best start of the season was second at
Watkins Glen International, where he finished 33rd following a crash. before the
2008 Pep Boys Auto 500 Montoya returned to drive CGR's No. 42 car for the
2008 NASCAR Sprint Cup Series. Montoya was 32nd in the
Daytona 500 despite running as high as second late in the race. CGR's decline in performance meant he had no top ten finishes or qualified within the top ten, leading to criticism from Ganassi. Jimmy Elledge became Montoya's crew chief after Wingo was moved to teammate
Reed Sorenson's squad before being replaced by
Brian Pattie. They promised to work together regularly to make Montoya more competitive. Although Montoya continued to struggle performance-wise attributed in part to the closure of teammate Franchitti's squad due to sponsorship issues, he finished in the top-ten at both road course races (sixth and fourth in the
Toyota/Save Mart 350 at Infineon and the
Centurion Boats at the Glen at Watkins Glen, respectively). He took pole position for the
Camping World RV 400 at
Kansas Speedway, but his lap was disallowed due to excessive gas pressure in his rear
shock absorbers. Montoya was 25th in the final championship standings, with 3,329 points. and a contract from Tost to return to F1 with Toro Rosso since his family felt comfortable in the United States. During the season, Montoya won no races but was more competitive and consistent with ten top-ten finishes and improved his qualifying performances in the first 26 races, This was due to his car's increased power, his developing experience and patience, and Pattie's calm demeanour. Montoya had been enough acquainted with the Car of Tomorrow by mid-2009, when he adjusted his driving style to slow down in order to be faster. In the
Aaron's 499 at Talladega, he qualified on pole for the first time in his Cup Series career before finishing second in the
Sunoco Red Cross Pennsylvania 500 at
Pocono Raceway. He was tenth in points after the second race at
Richmond Raceway and qualified for the
Chase for the Sprint Cup. A pole position in the
Sylvania 300 at
New Hampshire Motor Speedway along with six top-ten finishes put him as high as third place in the standings but was eliminated from title contention after a series of accidents. He was eighth overall with 6,252 points. He qualified better and increased his average finishing position over the first 21 races of the season, with eight top-ten finishes, two pole positions, Montoya qualified on pole for both the
Lenox Industrial Tools 301 in New Hampshire and the
Brickyard 400 at Indianapolis, but crashed in both races. Montoya started third in the
Heluva Good! Sour Cream Dips at the Glen at Watkins Glen and led 74 of the race's ninety laps to take his second (and final) Cup Series victory. The rest of the season saw him claim five more top-ten finishes and pole position for the
AMP Energy Juice 500 at Talladega. He was 17th in the final standings with 4,118 points. but his performance suffered as a result of NASCAR mandating a nose change. Montoya finished third in the
Kobalt Tools 400 at
Las Vegas Motor Speedway two races later, his best finish of the season. Montoya qualified on pole position for the
Auto Club 400 at Auto Club Speedway and in the
Crown Royal Presents the Matthew and Daniel Hansen 400 at Richmond in his first short oval track pole. Following Montoya's inconsistency in the first half of the season, which saw him drop down the points standings throughout the year, Ganassi replaced Pattie as the driver's crew chief by Jim Pohlman without Montoya's substantial participation before the
Brickyard 400 that July. He ended the 36-race season 21st overall with 932 points after eight top-ten finishes and no race wins. He remained with EGR for the
2012 season and was assigned
Chris Heroy as his new crew chief after Ganassi restructured his team. Montoya's trailing arm snapped during the season-opening
Daytona 500, causing him to crash sideways into the rear of a jet dryer transporting jet fuel and catching fire. During the season, he only had two top-ten finishes, which were eighth-place finishes at
Bristol Motor Speedway and Michigan. He was 22nd in the drivers' standings with a total of 810 points. He was slowed by mechanical problems and was involved in crashes in five of the first seven races of the season. Montoya started sixth and finished fourth in the
Toyota Owners 400 at Richmond after leading 67 laps due to a late race caution. Four races later, he took his best result of the season with a second-place finish in the
FedEx 400 at Dover after leading 19 laps and being overtaken by Stewart with three laps to go. Montoya was set to finish second in the
Toyota/Save Mart 350 at Sonoma but he ran out of fuel on the final lap and finished 34th. The rest of the season saw him secure five more top-ten finishes, with a best performance of third at Bristol. Montoya finished his final full-time Sprint Cup Series season 21st in the points standings, with 891. Montoya finished outside of the top-ten positions in both races. Montoya returned to NASCAR after a ten-year absence to compete on a one-off basis at the
2024 Go Bowling at The Glen driving
23XI Racing's No. 50
Toyota Camry XSE after accepting an offer from team president Steve Lauletta. He qualified 34th for the race and finished in 32nd. ==IndyCar Series==