It rises and falls like an empire at war, scaling the side of a mountain before ducking and diving through trees as it hastily advances down the far side. Every year an army descends upon it, laying siege to the countryside for a weekend while around them war is waged.

To most Australian motor sport fans Bathurst is Mecca, a place of spiritual enlightenment often experienced through the bottom of a beer bottle. It's one of the world's greatest circuits, so when the opportunity arose Christian Klien heeded the call to arms.

The Austrian has driven most of the world's great circuits in some of the most mouth-watering machinery on the planet. He's raced at Spa-Francorchamps in Formula One and won there in a Peugeot LMP1 sports car, but Bathurst poses a unique set of challenges.

"Spa is good in a Formula One car because it has very fast corners, very open corners," he says. "In a normal road car, like the Lotus, it would probably be really boring if you're used to racing at Spa in much faster cars. Blanchimont would be probably 160 km/h in the Lotus Exige, whilst in an F1 car we did it flat out at 290 km/h."

Bathurst suits GT cars, like the Lotus Exige Klien had been driving earlier. The narrow and steep circuit is a challenge, not like Spa which the Austrian promises is rather dull in anything much slower than a Formula One car, or an LMP1 car at a pinch.

Bathurst is Australia's own Spa-Francorchamps. It's no Nordschlieffe, but then at 20km long the Green Hell is just a bit silly, really. "This is more like… let's say a normal race track," agrees Klien. "You come around the same corner every two minutes, so it's more like a normal race circuit where the Nurburgring is so long, with so many corners." 154 of them to be exact - about one every 130 metres, but who's counting?

He laughs a lot. Relaxed, and happy, it's refreshing to see and was distinctly missing when we last spoke in Singapore 2010. Back then he was on the Hispania payroll as test and development driver, though in truth had done little other than drink espresso in the team's hospitality suite.

Hispania Racing Team was an experience, to say the least. The team had a relaxed attitude to routine maintenance (even brake pads weren't changed as often as you'd think) while pre-race preparations meant little more than dusting the car off after taking it out of the container.

He got the job at Hispania because of Colin Kolles, the pair having known each other since the days when Klien was a constant race winner in junior formulae before crossing paths again in Formula One. "He was actually running the team and solving all the problems. He did really an amazing job, but it just didn't have the budget."

Klien, veteran of more than 50 Grands Prix, was supposed to be the experienced figure in an inexperienced team. "They had Geoff Willis and he did some work in the background but his hands were tied because there was no money around," explains Klien. "By the end of the year I got a chance to do some races because the other drivers said they'd bring a lot of money, but they didn't." It was typical of the Spanish team, switching drivers as pocket books ran dry.

For Klien it harked back to his time as test driver at Honda when he was invited to audition with Force India, then known as Spyker. "They were not happy with one of their drivers so they asked me to test at Spa in the middle of the season," he recalls. Klien made an impression on Colin Kolles, who was managing the team, which would open doors later. However a racing return at that point was thwarted when Christijan Albers found the money to allow him to finish the season.

Pay drivers are now part of Formula One's staple diet in the way tobacco advertising once was; a driver's talent is linked to their bank manager's recommendation. "It's very frustrating," Klien admits. "For 2011 I was talking to a few teams, but everywhere you had to bring around $5million for a race drive. These days it is not enough to just be competitive; a driver is also required to provide sponsorship."

Klien has never had money; he didn't need it with Red Bull picking up the tab. He was one of the Austrian company's original three development drivers, and the first to reach Formula One. He was also the first to be put to the sword once the drinks company took over from Jaguar in the sort of shrewd move it has now become famous for. He could be bitter about it, and possibly is - he refuses to speak about his relationship with Dr Helmut Marko - but he's still thankful for the opportunities he had. "We didn't have the money to do motor sport so basically Red Bull paid for everything - all the lower categories until Formula One. That's very good, very positive," he admits.