It's quarter time in the NASCAR season - America's National Association for Stock Car Auto Racing. Nine of the 36 races have been run and won.

This was going to be the year Australian Marcos Ambrose made it big over there.

Ambrose, V8 Supercar champion in 2003 and '04 and third in '05, has been in the US five years now.

It was a brave move and he worked his way up through NASCAR's minor leagues to become a full-timer in the premier Sprint Cup series last year, finishing the season a creditable 18th.

His sights this season have been on making The Chase - the top dozen drivers who get to vie for the title over the final 10 rounds.

But his results over the nine races so far - 41st, 35th, 14th, 11th, 33rd, 11th, 11th, 17th and 37th - have left him 30th in the championship, 787 points behind the champion of the past four years and leader again this season, Jimmie Johnson.

The gap to 12th-placed Jeff Burton is a less daunting 295 points, but there are 18 other drivers to climb over to get up there.

As a boy from Tasmania, growing up in karting and Formula Ford, Ambrose's ambition had been Formula One.

He had an open-wheeler heritage - his father, Ross, was a co-founder of the Van Diemen company in Britain that for many years was the world's leading constructor of Formula Ford cars.

The younger Ambrose won the Formula Ford Eurocup 11 years ago and was third in the British championship, advancing to Formula Three before finding it financially beyond reach.

Coming home to Australia he was an instant success in V8 Supercars and his five years in Ford Falcons were a high for him and the manufacturer.

The only thing missing from Ambrose's CV was a Bathurst 1000 victory, but he wasn't waiting around to achieve that.

His sights had turned to NASCAR, with Ford's blessing and funding - it had money in those days.

He teamed up with Wood Brothers, which had been a powerhouse in American stock car racing years before, and an advertising man, Tad Geschickter.

Few foreign drivers dare venture into NASCAR. Colombian firebrand and F1 refugee Juan Pablo Montoya is one who has, with some - but not ultimate - success.

NASCAR is a huge but peculiarly American, predominantly southern American, form of racing for thumping V8 sedans, with fields of 43, mainly on oval tracks, ranging from 800 metres to superspeedways of more than 4km, and speeds averaging around 200mph (320kmh).

The races are long - often 500 miles or 800km, and up to 960km - and the season grueling, but Ambrose applied himself like a man possessed.

He started in what NASCAR calls its truck series, or what Australians know as utes.

Then he had two years in the Nationwide Series, the No. 2 NASCAR division, in a Ford Fusion car, regularly finishing in the top 10, often against many of the big boys from the Sprint Cup.

He even won a Nationwide race, but it was on a road course - Watkins Glen in upstate New York, once home to the US F1 grand prix - and got to do a few Cup races.

Last year he graduated full-time to the Cup series, and by now he was driving a Toyota Camry - although NASCARs are, or should be, stock standard below the body.

Former Cleveland Cavaliers basketball star Brad Daugherty had become a partner in the team with Geschickter and his wife Jodie.

They have a technical alliance with the bigger team of Michael Waltrip, a two-time Daytona 500 winner in the twilight of his driving career and brother of three-time Cup champion Darrell Waltrip.

It's not in the league of the Hendrick, Childress or Joe Gibbs teams, but it looked like a good connection.

Four top five finishes - two on ovals, including the frightening Talladega superspeedway in Alabama, the other two on road courses - and 18th overall was a commendable 2009 for Ambrose.

So the slide to 30th this season is surprising - and alarming.

To make matters worse, last week Ambrose's crew chief Frank Kerr was fined US$75,000 for an illegal radiator pan on his Toyota. It was overweight and deemed "unapproved ballast".

"It was just a big misunderstanding," Ambrose said. "It wasn't intentional - wasn't anything to cheat."

Ambrose was docked 50 points in the drivers' championship and the team lost 50 points too, which could yet prove crucial.

The team needs to be in the top 35 at the end of the season to guarantee Ambrose a place in the field next year.

Unlike European and Australian racing, which is often processional on road and street courses, NASCAR is invariably close, with lots of passing, argy-bargy and frequently terrifying crashes.

But the rewards are big - millions of dollars in prizemoney and endorsement opportunities.

NASCAR demands different skills, especially in the art of drafting - or slipstreaming - on the ovals.

Yesterday's race at Talladega had a record 88 lead changes, with 29 drivers heading the pack at different times.

Not Ambrose, although he was as high as third early on.

He had a minor collision with last year's Talladega winner, Brad Keselowski, at one-third distance, after which the American gave him a public spray.

"I don't know how they pit in Australia, but apparently it's from the third lane," Keselowski chided.

Worse was to come. Fighting his way back from a lap down after repairs to his car, Ambrose was an innocent victim of a nine-car pile-up in the closing stages before Kevin Harvick outdragged this year's Daytona 500 winner, Jamie McMurray, to win by 0.012 seconds.

Ambrose - a father of two young girls who spends nine months of the year based at Charlotte, North Carolina, and the other three relaxing in Tasmania - keeps his chin up through the adversity.

"It was just one of those tough days," he said. "By the end of the race the car was good enough to run with the leaders.

"We were in a good position. It's a shame ... but we'll bounce back and have a fresh start next week at Richmond (in Virginia)."

A legendary NASCAR figure, long-time Charlotte speedway promoter H.A. "Humpy" Wheeler, has become a mentor to Ambrose - and calls him the Dale Earnhardt from Down Under.

Earnhardt was a seven-time Cup champion known as The Enforcer who died in a crash on the last lap of the 2001 Daytona 500. His son, Dale Junior, is now the sport's most popular driver despite little major success.

"People here (in America) just haven't seen Marcos in the kind of equipment, say, Jeff Gordon or Tony Stewart (NASCAR multiple champions) has," Wheeler says.

"He's a much better driver than where he's finishing. He's passing probably as many cars as anybody on the race track. He's just having slow pitstops. That's not his fault.

"But right now if you'd ask Jimmie Johnson or one of the other leading drivers who they'd least rather have on their rear bumper, they'd probably tell you it would be Marcos Ambrose, because he's driving extremely hard.

"When you see him finish 11th, if he had the pitstops (of the top contenders) he'd probably be second or third.

"I think Marcos has at least four or five really good years in front of him.

"Unlike some of the drivers that have come in here from foreign countries, Marcos primarily has been driving heavier cars, so he's used to handling the heavy cars.

"I think he's poised to win a lot of races."

Wheeler is a true believer in Ambrose, but the jury will be out a fair while yet on whether the man they called the Devil Racer in America can truly conquer NASCAR.