HOMESTEAD, Fla. (AP) — NASCAR's season of doom and gloom sputters toward the checkered flag with a stout championship field but the inability to distance itself from everything that's gone wrong in this trying year.

Martin Truex Jr.'s team is closing after the race because his primary sponsor is leaving the sport. Kevin Harvick's team was caught cheating then justified using an illegal spoiler because other teams were doing it first.

Fans hope the four championship-contending cars are legal but won't know for sure until the cars have been inspected, long after the champagne celebration is over, because the culture of cheating in NASCAR lingers.

Television ratings hit a low in 26 events this year, and the cumbersome rulebook, a vulnerable inspection process and NASCAR's officiating has received far too much attention of late.

NASCAR may or may not be for sale, the France family doesn't often speak publicly and their intentions remain private. But the August drunk-driving arrest of Brian France forced a change at chairman and a definitive shift in NASCAR leadership. It was Ben Kennedy, the 26-year-old great grandson of NASCAR's founder, who represented the series during the Truck Series celebration.

Next up is the Cup title race Sunday at Homestead-Miami Speedway that pits reigning series champion Truex against Harvick, Kyle Busch and Joey Logano in a winner-take-all finale. It's the strongest final four since NASCAR adopted this format in 2014 — the four drivers combined to win 22 of 35 races this season — but the on-track action has been overshadowed time and again by off-track problems.

On the eve of the title race, Joe Gibbs was under scrutiny for what some perceived to be race manipulation: Gibbs made a team decision that gave contender Busch an edge. Gifting Busch the top pit stall that teammate Denny Hamlin had earned seems minor, but it quickly became the most intriguing elements of the weekend. Among the other highlights? Jimmie Johnson shaved his beard after seven or so years as a tribute to Lowe's — the only sponsor he's had in 18 years — in its final race before the company leaves NASCAR.

Truex advised tuning out the noise.

"I think the racing has been unbelievable this season," Truex said. "A lot of action, a lot of big moments on the racetrack. I don't really worry too much about the stuff that happened away from it. I think the sport is in a good place and heading in a good direction."

It's a sound endorsement from a journeyman driver who hit the jackpot when paired with single-car Furniture Row Racing, a mid-level team based in Denver that defied all odds and won last year's Cup title. But that title wasn't enough to keep the team's main sponsor from leaving and Furniture Row will close after Sunday's race rather than try to compete on the cheap.

Truex and crew chief Cole Pearn will join Joe Gibbs Racing next season, and Sunday is a final opportunity for one last celebration with the Furniture Row team.

"You can imagine how sick you feel when you see it coming to a close," said FRR President Joe Garone, who like Truex distanced the team's closing as an indictment of the overall health of the sport. "NASCAR is still a place to be for corporate sponsorship. There's no question about it."

Truex, a four-time winner this season, is trying to become the first back-to-back champion since Johnson won his fifth consecutive title in 2010. He's part of the so-called Big Three along with Busch and Harvick, winners of a series-high eight races each this season.

But Harvick's winning car was deemed illegal after two of his wins, most recently two weeks ago at Texas when NASCAR found the spoiler on the Stewart-Haas Racing entry was not from the mandatory vendor.

"Like, the first question across my mind was, 'How long? How long has that been going on? What else are they doing?'" Busch wondered.

Busch and Harvick have matched each other win-for-win all season, and even though NASCAR penalized Harvick's team, Busch is not alone in wondering if the entire season is tainted.

Harvick thrives in controversy and doesn't expect that to change Sunday.

"For me, there's always some incentive in proving to people that you can do something that isn't what they think you should do," Harvick said. "Last week it was (said) 'This penalty is going to slow them down.' The mentality of the race team is to always push the limits. When they back you against the wall, make it better than it was before."

He's racing without crew chief Rodney Childers, who was suspended for the final two weeks of the season for the illegal spoiler. Childers stayed at the North Carolina shop last weekend but is expected to be somewhere at Homestead on Sunday. He's barred from the garage, but NASCAR will allow him to celebrate with his team if Harvick wins the title.

Harvick has made the final four every year but once since 2014, the year he won the finale and the championship. Busch won in 2015, Truex last year and a second title for any of The Big Three would give NASCAR just its second active driver with multiple championships. Johnson has seven, and none of his current peers has more than one Cup title.

Busch, meanwhile, was the highest-qualifying title contender at second, but it was one spot behind Gibbs teammate Denny Hamlin. Debate began immediately about Hamlin's right to choose the first pit stall, which is a clean exit off pit road, where the race may ultimately be decided.

Busch felt it was too big an ask to get Hamlin to forfeit that perk, and Hamlin a year ago denied the same request from Truex. But Gibbs decided this one and had Hamlin choose the second-best pit stall with his first selection. It gave Busch, picking second, the premium spot but earned the team a wave of criticism for gifting Busch a benefit over the other three contenders.

"Anything like this always stops with me," Gibbs said. "If somebody is upset, they need to be upset with me."

As the Big Three weaved through their individual issues, Logano just went fast.

He topped the leaderboard in the final two practice sessions of the season, not one of his best but perhaps the one that will lead to his first championship. Logano was on track to win the title in 2015 but a feud with Matt Kenseth contributed to Logano being locked out of the finale. He finished second the next season, missed the playoffs last year and used a late-season push to grab a spot in Sunday's race.

Logano actually thinks he's the favorite based on how well his Team Penske crew has been running, but Busch thinks a Logano championship would spoil this season dominated by The Big Three.

"He's been there. He's been consistent. He's been good. He hasn't necessarily performed to the level of The Big Three, and that's no shake on them at all, it's just the fact of the matter," Busch said. "So if he wins the title over the rest of us, then that would certainly be a little bit more disappointing."

It's a possibility, though, because all four drivers excel at intermediate tracks like Homestead. The Big Three has combined to win all but four races on the tracks between 1.33 and 2 miles, and Logano has an average finish of fifth on the intermediate tracks in these playoffs.

This format was designed to award the first playoff contender across the finish line the Cup title, and the champion the last four years has also won the race. The contenders believe that will be the case again Sunday and hope the race itself will be good enough to send NASCAR into the offseason on a high note.

Representatives from the four championship teams held a news conference at Homestead and insisted the sport is moving in the right direction. There has been a sense of calm since Jim France replaced his nephew as chairman and CEO following Brian France's arrest, but there's also uncertainty about the France's long-term plans. Reports have indicated the France family wants to sell some or all of NASCAR, and last week NASCAR made a move to buy all the public shares of sister company International Speedway Corp.

It's also going to be a rocky offseason with NASCAR rolling out new rules next year in an effort to improve the racing. The inspection process continues to be fine-tuned and Harvick's illegal spoiler has forced the sanctioning body to take a hard look at how it can curb the rampant cheating that teams do under the guise of "pushing the envelope" or "finding gray areas" of the rulebook.

The championship race may be fantastic and perhaps enough to temporarily forget all of this year's issues. Even if it doesn't, Gibbs believes everything will smooth itself out.

"I know that there's downturn, but I would just say that there's so many positives to this and I think NASCAR is working extremely hard," Gibbs said. "A lot of sports are going through a time where there's trouble and they've got to work hard, and I think we're certainly working hard from Jim France on down. It's exciting. It's kind of exciting where we are."

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