AVONDALE, Ariz. -- Kyle Busch, contrite and remorseful, promised Friday to change his behavior and conduct himself in a way that will restore the respect he lost with his road rage incident at Texas.

It's a long way back for Busch, and he'll be on a very short leash.

Busch has been warned by M&M's that the primary sponsor will not tolerate any more incidents by him, and team owner Joe Gibbs said the driver is still facing further punishment for wrecking Ron Hornaday Jr. under caution in last week's Truck Series race. NASCAR suspended Busch from all on-track activity at Texas, fined him $50,000 and placed the driver on probation through the end of the year.

It led to a frantic week of behind-the-scenes negotiations with Joe Gibbs Racing and sponsors who viewed Busch's latest incident as the final straw for the polarizing driver.

Firing him was not an option, Gibbs said.

"In a situation like this you can make one or two decisions. One would have been devastating and really discouraging for everyone around him and for the sport," Gibbs said. "What I've chosen to do, I want to support Kyle, and feel as if this could have a positive impact on Kyle and I am committed to him as a person. I like him. We've gone through a lot together. We're looking forward to a long relationship."

Busch was thankful for the support during what he called "a trying week" and admitted he worried he might be fired for the second time in his career. Busch was let go from Hendrick Motorsports at the end of the 2007 season when the team made room for Dale Earnhardt Jr.

"I'm apologetic for everyone having to go through this situation. There's no one to blame but myself. Joe has been a huge supporter of me and can't say enough about him," Busch said.

"Was there a point in which I thought, 'Do I have a ride?' Of course there was. I thought that (it might happen). Was there a point in which Joe ever told me that, 'Hey, we're looking at terminating this?' No."

But there had to be a point Busch was worried the decision could be out of Gibbs' hands.

The fallout from Busch losing his temper at Texas stretched deep into the sponsorship side of NASCAR, where every team is heavily dependent on funding from outside businesses. Although M&M's parent company, Mars Inc., has a contract with JGR, company officials wrangled with JGR all week over whether they wanted Busch to represent the brand anymore.

Gibbs admitted Friday the team was in limbo most of the week, unsure if NASCAR would suspend Busch longer and if M&M's would refuse to allow him in the car.

Ultimately, M&M's did withdraw from the final two races of the year, but Gibbs put longtime partner Interstate Batteries on the No. 18 Toyota. Gibbs would not discuss whether the team had to refund money to Mars, if Busch will collect salary these final two weeks, or if Interstate Batteries had to pay to get on the car.

But Interstate chairman Norm Miller said his 20-year relationship with Gibbs -- his company was JGR's first sponsor -- was the primary reason he stepped up for Busch. Interstate sponsored Busch in seven races this year in NASCAR's top three series.