Don't count on them doing it now.
After tying Cale Yarborough's 30-year mark as the only driver with three straight championships, Johnson and his crew chief were already thinking about going after No. 4.
"I could go race again next week and start the season and go for four," Johnson said after Sunday's finale at Homestead-Miami Speedway. "It's on our minds. It's not that we're chasing a number, we just know what we're capable of. We know we can do better. It's a search to do the best we can."
Knaus, the first crew chief in series history to win three straight, even offered to report to work Monday morning to start their pursuit.
He was only partly kidding.
"We want four. Why not? That's why we're here," Knaus said. "We can definitely bid for four. Give me a reason why not."
Carl Edwards could certainly offer a reason or two after winning Sunday's race - his series-best ninth victory of the season - only to fall 69 points short of wresting the Sprint Cup trophy away from Johnson. Edwards led a race-high 157 laps, and won despite running out of gas as he crossed the finish line.
Johnson won the title by finishing 15th.
"We won more races than Jimmie (seven), and we ran with him when he won," Edwards said. "I know they'll enjoy this championship, but they knew we were here."
Indeed they did, constantly looking in the rearview mirror as Johnson chased Yarborough's mark.
Yarborough won his three titles 30 years ago, under a different scoring system and in a very different NASCAR. He accomplished his feat when drivers scraped together the cash they needed to race, and the champion was the guy on top at the end of a long grueling season.
Johnson's titles have been won in the glitzy new Chase to the championship format, where the best 12 drivers compete over a 10-race sprint to the title.
Johnson and his Hendrick Motorsports team have mastered the system, proving themselves unbeatable in their pursuit of Yarborough's mark. They've won their titles with consistency - he finished outside the top 10 just twice in this Chase, a 15th-place finish at Texas - and by winning eight of the last 30 Chase races.
They've also gotten very rich along the way: Johnson has won more than $2 million in the 10 Chase races this year. Yarborough earned a combined $1.63 million in all three of his championship seasons.
Although the industry was keenly aware of its front row seat to history, the celebration seemed subdued because of the economic crisis that's finally found its way to NASCAR. The Big Three automakers are crumbling, car owners are struggling to find sponsorship, and widespread layoffs are expected Monday, when teams could combine to let go up to 1,000 employees.
Just this weekend, NASCAR said it would suspend all testing next year to help teams save millions in their 2009 budgets.
"The real risk is race teams folding," said Jack Roush, Edwards' car owner. "The bigger concern I've got is we keep the racing affordable, the race teams affordable for the sponsors, and we're able to keep these other race teams in business."
Had this crisis hit earlier, and the testing ban was in place this season, Johnson very well might not have won the title. He struggled at the start of the year in adapting to the full-time use of NASCAR's current car, so he and Knaus embarked on an aggressive testing schedule that helped them catch the competition by late summer.
By the time the Chase began in September, Johnson drove right past them.
"It's what we work for, it's what we do," Knaus said. "We don't want to do anything but race and win races and win championships."
When Edwards won back-to-back races at Atlanta and Texas to take a bite out of Johnson's points lead, Johnson rebounded with a win at Phoenix last week to make Sunday's drive a mere formality. He needed only to finish 36th or better to win the title, but got off to a rocky start when he qualified 30th.
He wasted no time driving through the field at the start of the race, and picked up at least one position a lap at the start. He would have finished higher, but he stopped for fuel near the end.
Edwards pushed it to the limit, knowing he had to win the race, lead the most laps and pray for Johnson to have some trouble to win his first title. But he was a gracious runner-up, and after his trademark celebratory backflip, he walked over to Johnson's passing car on the track to congratulate him.
"At least we can lay our heads down tonight and know we won some races and just got beaten by a true champion," Edwards said.
It was the second straight night Edwards won the race, yet still came up empty in the championship bid. He won Saturday night's Nationwide Series event, but came up 21 points short of champion Clint Bowyer. Edwards' win Sunday chopped 72 points off Johnson's margin.
Kevin Harvick finished second and was followed by Jamie McMurray and Jeff Gordon, who finished the year winless for the first time since his 1993 rookie season. But the four-time series champion didn't let his own struggles dampen his Hendrick teammate's celebration, as Gordon walked to the victory stage to offer his congratulations.
Bowyer finished fifth and was followed by Kasey Kahne, Travis Kvapil and Casey Mears.
Tony Stewart, in his final ride for Joe Gibbs Racing after a successful 10-year run, wound up ninth after giving up the lead late in the race to pit for fuel.
"We didn't win the race, but they knew we were here and we showed why we've been champions and won 33 races with this team," said Stewart, who is leaving to run his own race team next season.
Martin Truex Jr. rounded out the top 10.
Matt Kenseth, who won the 2003 series championship in the final year of the old points system, led late but ran out of fuel and finished 25th in his first winless season in seven years.
"We just can't seem to get things to go our way," said Kenseth, who was frustrated teammate Edwards could stretch his gas but he could not. "I don't understand how he can make power and still get that much better fuel mileage than us. I had such a big lead, I was just riding around."