Busch was released from Roush Racing at the end of 2005 and joined Penske Racing South in 2006.
Busch had asked team owner Jack Roush to let him out of his contract at the end of 2005, but Roush initially refused.
However, after Chip Ganassi released Jamie McMurray from his 2006 contract, Roush decided to release Busch when Roush learned that Busch already signed a contract with Roger Penske before the season ended.
Busch's last race with Roush-Fenway Racing and 2005 was at Texas before the final two races; because he was parked by NASCAR for an incident with the police (see below).
Busch appealed and a misunderstanding on the police's part was cleared before the races but the parking penalty was held in place.

McMurray, who was originally slated to join Roush in 2007 to drive the No.
6 (which ultimately went to David Ragan), instead replaced Busch in the No.
97, which was then renumbered to No.
26.

In the 2006 season, driving for Penske, Busch scored one win at Bristol Motor Speedway in the Food City 500, his fifth win at the track.
Busch celebrated the victory by getting out of his car and making a snow angel on the track, due to snow that had fallen at the track that weekend.
He also won six poles and had seven top fives and twelve top-ten finishes but finished 16th in the final standings.
He also made his Busch Series debut for Penske in the No.
39 Dodge at Texas Motor Speedway, winning in his first race.
He ran six more races that season and picked up a second win at Watkins Glen International by holding off Robby Gordon on the final lap.
Gordon and Busch on the final lap struggled for the win but it resulted in Busch holding onto the lead in the outer-loop to seal up the win.
In victory circle, Busch thanked Gordon for a fight for victory and said that the struggle reminded him of his 2003 Carolina Dodge Dealers 400 at Darlington when Ricky Craven beat Busch by one inch to win the race after a 2 lap-long struggle to the checkers.

In the 2007 season, Busch had two wins, one pole, scored five top-fives, and ten-top tens through 26 races and qualified for the Chase for the Sprint Cup.
Busch's on-track performance increased noticeably after the addition of Pat Tryson as his crew chief midway through the season.
He also ran four more Busch races, earning 2 top-five and 3 top-ten finishes.

In 2008, to make sure rookie teammate Sam Hornish Jr. would be guaranteed a starting spot in the season's first five races, the owner's points from Busch's No.
2 car were transferred over to the No.
77 car driven by Hornish.
Busch would still be guaranteed a starting spot, due to NASCAR's Champion's Provisional Rule, which states that the most recent series champion not in the top 35 in the previous season's final owner points automatically qualifies for a race. (
With his 2004 championship, Busch was by several years the most recent).

At the 2008 Daytona 500, Busch was contending to win and had a fast car on the final lap capable to win.
He and his teammate Ryan Newman got by Joe Gibbs Racing rivals, Tony Stewart and Kurt's brother Kyle on the final lap and Kurt decided to instead of trying for the win himself, push Newman to victory.
In turn 4 Newman cleared further challenges and won the race, thanking his win on Busch in victory circle.
It was Roger Penske's first Daytona 500 win and it made Penske one of the few owners to win both the Indianapolis 500 and Daytona 500 in an owner career.

On June 29, 2008, Busch broke a 29-race winless streak at New Hampshire Motor Speedway when the Lenox Industrial Tools 301 was called due to rain on lap 284.
It was his first win since Michigan's late summer race in 2007, and his fourth win since joining Penske Racing and 18th overall.

He began his 2009 season at the 2009 Daytona 500, he was involved in a wreck on lap 124 when Dale Earnhardt Jr. swerved into Brian Vickers.
Vickers shot up the track and hit the wall, ricocheting into Denny Hamlin, who came down into Busch.
He then spun into the grass along with eight other drivers including his brother Kyle.
Busch made numerous pit stops to repair th
Busch was released from Roush Racing at the end of 2005 and joined Penske Racing South in 2006. Busch had asked team owner Jack Roush to let him out of his contract at the end of 2005, but Roush initially refused. However, after Chip Ganassi released Jamie McMurray from his 2006 contract, Roush decided to release Busch when Roush learned that Busch already signed a contract with Roger Penske before the season ended. Busch's last race with Roush-Fenway Racing and 2005 was at Texas before the final two races; because he was parked by NASCAR for an incident with the police (see below). Busch appealed and a misunderstanding on the police's part was cleared before the races but the parking penalty was held in place.
McMurray, who was originally slated to join Roush in 2007 to drive the No. 6 (which ultimately went to David Ragan), instead replaced Busch in the No. 97, which was then renumbered to No. 26.
In the 2006 season, driving for Penske, Busch scored one win at Bristol Motor Speedway in the Food City 500, his fifth win at the track. Busch celebrated the victory by getting out of his car and making a snow angel on the track, due to snow that had fallen at the track that weekend. He also won six poles and had seven top fives and twelve top-ten finishes but finished 16th in the final standings. He also made his Busch Series debut for Penske in the No. 39 Dodge at Texas Motor Speedway, winning in his first race. He ran six more races that season and picked up a second win at Watkins Glen International by holding off Robby Gordon on the final lap. Gordon and Busch on the final lap struggled for the win but it resulted in Busch holding onto the lead in the outer-loop to seal up the win. In victory circle, Busch thanked Gordon for a fight for victory and said that the struggle reminded him of his 2003 Carolina Dodge Dealers 400 at Darlington when Ricky Craven beat Busch by one inch to win the race after a 2 lap-long struggle to the checkers.
In the 2007 season, Busch had two wins, one pole, scored five top-fives, and ten-top tens through 26 races and qualified for the Chase for the Sprint Cup. Busch's on-track performance increased noticeably after the addition of Pat Tryson as his crew chief midway through the season. He also ran four more Busch races, earning 2 top-five and 3 top-ten finishes.
In 2008, to make sure rookie teammate Sam Hornish Jr. would be guaranteed a starting spot in the season's first five races, the owner's points from Busch's No. 2 car were transferred over to the No. 77 car driven by Hornish. Busch would still be guaranteed a starting spot, due to NASCAR's Champion's Provisional Rule, which states that the most recent series champion not in the top 35 in the previous season's final owner points automatically qualifies for a race. (With his 2004 championship, Busch was by several years the most recent).
At the 2008 Daytona 500, Busch was contending to win and had a fast car on the final lap capable to win. He and his teammate Ryan Newman got by Joe Gibbs Racing rivals, Tony Stewart and Kurt's brother Kyle on the final lap and Kurt decided to instead of trying for the win himself, push Newman to victory. In turn 4 Newman cleared further challenges and won the race, thanking his win on Busch in victory circle. It was Roger Penske's first Daytona 500 win and it made Penske one of the few owners to win both the Indianapolis 500 and Daytona 500 in an owner career.
On June 29, 2008, Busch broke a 29-race winless streak at New Hampshire Motor Speedway when the Lenox Industrial Tools 301 was called due to rain on lap 284. It was his first win since Michigan's late summer race in 2007, and his fourth win since joining Penske Racing and 18th overall.
He began his 2009 season at the 2009 Daytona 500, he was involved in a wreck on lap 124 when Dale Earnhardt Jr. swerved into Brian Vickers. Vickers shot up the track and hit the wall, ricocheting into Denny Hamlin, who came down into Busch. He then spun into the grass along with eight other drivers including his brother Kyle. Busch made numerous pit stops to repair th
Kurt Busch