Though the 25-year-old Englishman was yesterday loathe to discuss exactly how much it cost him personally to buy his way out of a binding contract with Sir Frank Williams' team for 2006, he did admit: "Trust me, it hurts."
Button, however, looked nothing like a man who is hurting.
"The last few days have been the high point of my season," he said, a broad smile on his face and a tangible air of relief wrapped around him like a cloak. "After resolving this issue with Frank Williams it is unbelievable how much more relaxed I feel. Now I am able to focus on what is important, which is the racing.
"I'm ecstatic that we have sorted the situation between Frank and me. The contract was between him and me and that was how we sorted it. It was not a nice situation to be in, but I'd like to say thank you to him because we were able to stop it before it went any further. It was not as if I was just walking away saying I don't want to drive for you.
"We came to an agreement as I tried to resolve the issues the best way I could. We had as many meetings as possible and talked the situation through many times. It was down to me and not down to the people around me, and I think that made the difference.
"Obviously when it all finally happened I was a very happy person. We all knew what we wanted, and it's best for all of the people involved. I'm so excited about the future. This is where it starts with BAR-Honda. It's not been cheap for me, but I'm sure it will be worth it for the future."
Button is believed to have a deal worth £50m on the table from BAR shareholder Honda over the next five years, which will more than compensate him for the money he has personally had to pay Williams for his release.
Well aware of the irony that this is the second year in a row at which everyone has arrived in Brazil to discover that he will be staying with BAR - except that this year he wants to and last year he did not - and that for the foreseeable future he now seems to have settled on the team that he wants to stay with following his previous prevarications, he added: "It is never 100 per cent that any team can challenge for the world championship, but the determination and dedication of BAR-Honda is beyond anything I have seen in F1, how the Japanese and British sides of the operation work together and how focused they are on our goals of winning the titles."
Yesterday BAR confirmed that Rubens Barrichello will be Button's partner. "I know Rubens reasonably well," Button said. "He has a lot of experience and brings a lot to the team. He's a very capable driver and it's good to have a new challenge. Off the circuit I think we will work really well together, while on it we will be deadly rivals."
Yesterday it was also confirmed that there will be a United States Grand Prix at Indianapolis next year, despite the fiasco of this year's six-car event and fears that organiser Tony George would spurn F1 for good. The Indianapolis Motor Speedway has announced a date of 2 July for their race.