Penske Racing has announced that they have agreed to a mutual split with NASCAR racer Kurt Busch, following a season in which the driver was embroiled in several behavioral scandals on and off the track.

Busch has a history of altercations in NASCAR, including incidents with several other drivers. The straw that broke the camel's back, however, was at the Homestead-Miami Speedway during the closing race of the season. After Busch's transmission failed early, he left the track and made an obscene gesture in frustration - which happened to be in the direction of First Lady Michele Obama's motorcade, prompting speculation about whether this was inadvertent or intentional.

That might not have been enough to end Busch's relationship with Penske if it was indeed unintentional, but what happened next couldn't be mistaken. A camera caught Busch, out of his car, launching a profanity-laced tirade at ESPN interviewer Dr. Jerry Punch and his camera crew. The footage was uploaded to YouTube and has since went viral.

From there, it was somewhat academic that Busch would not be back with Penske for the next season. The statement that Penske released indicated that both parties were hoping to move on.

"It's important for people to understand the nature of what we've done,'' Bud Denker, a senior vice president for Penske Corporation, told ESPN. "It's a mutual separation. Kurt came to the conclusion and we have as well that it's time to move on. Kurt has been a terrific driver for us. He's a friend. We have been working with problems and issues in the past. It's well documented by everyone. As we looked at 2012 and beyond it was time to move on based on that incident at Homestead.''

Denker went on to say that Busch was unhappy with the performance of the team on the track, which was apparently the source of his frustration and unhappiness.

In his own statement, Busch did not allude to any issues he had with the team's ability. However, he did make reference to the fact that his behavioral issues were a contributing factor to the split.

"I am grateful to Penske Racing for six very productive years," said Busch. "Together we won a lot of races - 16 in all. Leaving a great organization and a lucrative contract is not easy, but it's an important step for me and allows me to take a deep breath to work on things that can make me a better driver and a better person."

Busch's brother Kyle, who also races in NASCAR, has had issues with his behavior as well. He was fined and suspended this season for an incident in which he purposely caused another driver to crash after an on-track dispute. However, it currently appears that Kyle will ultimately remain with his team for the next season.

The focus will now turn toward finding a replacement for Busch on the Penske team, which is sponsored by Shell/Pennzoil. One of the criteria for the sponsorship deal was that Penske keep a "championship-caliber" driver on the team, but those are obviously not easy to find.

Denker indicated that one possibility for replacement could be David Ragan, who won the Daytona 500 this year. Ragan is an up-and-coming driver who is currently signed to Roush Fenway Racing, but doesn't have a sponsor as of now, as UPS has pulled out of the competition.