Not long before the end of the 20th century, a remote automotive outpost took a bare-arsed bet on a concept for its first full-sized coupe in 20 years.

Far from being an unnoticed blip on a distant star, the Commodore Coupe concept would re-align the orbit of General Motors itself and make Holden the magnetic centre of its muscle-car galaxy.

Eleven years on, more cataclysmic forces are pulling GM in a new direction. But Holden's 10-year trajectory produced Monaro, the all-Australian pony-car that went on to earn one of America's most iconic badges: Pontiac GTO. It put Australia in the box seat to develop GM's new generation of rear-drive architecture, the Zeta, which in turn put another all-Australian model, the VE Commodore, on the boat to the US wearing Pontiac badges.

It culminated, perhaps inevitably, in Australia designing and engineering an all-American icon, the new Camaro. It was a surrogate project, never destined to be built or sold here. Unlike the third, and perhaps most dazzling star that might have embodied the best of everything.

We know it as Holden Coupe 60. By the time it was unveiled at the 2008 Melbourne motor show, ostensibly in celebration of Holden's 60th anniversary, the car that had been developed as the VE-generation Monaro had been dead in the water for three years. "Eventually it was shelved as not the thing to do; for the show car we resurrected it and put carbon all over it," shrugs Holden's exterior design manager, Peter Hughes, for whom Coupe 60 was very much his baby.

Back in 1998, Hughes was on the team of the now near-legendary Holden design revolutionary, Mike Simcoe. He confirms the furtive Friday nights and surreptitious Sundays that the team spent on the largely unauthorised Commodore Coupe clay. "I recall coming in one Sunday and doing a full-size tape that we were going to show [engineering boss] Tony Hyde. We just let a few important people know that we were going to make a full-sized clay.

"These days, [Holden is] far more global, so you have to let people know before you can get things done," he smiles. "But back in those days, we had a bit more flexibility to hide the costs [involved].

Yeah, it was very sneaky...

"We were all pretty young when we did it, then it was a big success when it came out. It put Holden - and more specifically, Design - on the map as a stand-alone department that could do things
for GM globally."

Of course, it was GM's product prophet Bob Lutz who saw the inner beauty of the Commodore Coupe. His nod gave the green light for the first new Monaro coupe since the HX LE of 1976, and also put it in the frame for the US market from 2003.

Monaro famously took just 22 months from show to go. It was hard work, but Hughes knows only too well that a lot of it had been done already. That's the culture of design within Holden: any concept they do is already very close to a production reality (excepting Richard Ferlazzo's wild Efijy hotrod from 2005).

"There's no point doing something wacky," Hughes says. "We can't spend millions and millions of dollars on show cars without the intention of going forward into production. It's pretty well known in the GM world that when Holden does a show car it's usually quite buildable and quite realistic.

"The Coupe 60 was done as a coupe study on VE architecture, similar to Monaro, similar architectural changes. That's not unknown. It's the same when we do any new architecture. We do all the variants that could possibly go ahead."

Lutz's sudden fondness for his antipodean outpost would also, of course, create a global foundation for Holden's next generation of Commodore. In Zeta, Lutz would have a world-class platform capable of underpinning a variety of enthusiast US models.

Matter-of-factly, the design boys set about doing studies of that family. Sedan. Ute. A new twist on wagon. And a coupe.

I hear it before I see it. The sharp, Ferrari-like bark seems an octave too high for a 6.0-litre, Gen IV V8. Put that down to a straight-through exhaust system that exits, race car-style, via side pipes. The sound, and the admitted absence of a cat converter, contrasts with the Coupe 60's green credentials, namely AFM cylinder shutdown and E85 ethanol-blend capability.

Still photography can't do it justice because Coupe 60 is live-action. Light plays and pours over it like mercury as this one-off, hand-built creation motors across the Lang Lang skidpan, rumbles to a halt in front of me and, signing off, cracks a lop-sided grin of right lock.

Two weeks of revolving on a motor show stand doesn't touch 10 seconds of this.

I'm later told that the eye-riveting, titanium effect of the paint (which Hughes named Diamond Silver) is achieved by an undercoat of black, followed by four coats of chrome silver. The same process is used on a couple of the Camaro's wheel options, the number of chrome coats determining the darkness of the final finish.

The body shape is a completely logical, yet understandably emotional step from the VE sedan. There's the zip front overhang, trademark solid surfaces hitting crisp lines, and obvious cues like the hockey stick at the base of the C-pillar. But with its more raked windscreen, 60mm lower roofline, 150mm longer doors (with a properly fast cut-line, unlike the poor old Monaro's) and 123mm chopped from its upturned tail, Coupe 60 is a more exaggerated and unrestrained expression of VE's proportions.

Even alongside Camaro, this four-seater coupe, on the same wheelbase as its large sedan sister, has all the tension of a sports car.

But as I clamber into the carbonfibre-sided channel of the passenger's seat - a barrier less immovable than the design department minder in the driver's seat - there seems to be even better accommodation than in a VE sedan. The instrument panel is familiar, but different, with the driver's side graced with a floating instrument pod atop the steering column.

Despite the recognisably thick A-pillars and the prevalence of black interior colour - which, here, brings more focus onto the variety of textures used - there's space and light everywhere.

It's the pillarless design that absolutely opens the cockpit. The black, high-waisted interior of the VE Commodore (and the Camaro even more so) feel almost dungeon-like by comparison. Remember, underneath Coupe 60's hand-made fibreglass and carbonfibre panels, is literally a pretty standard, donor Commodore SSV, gas-axed above the sills.

Hughes confesses the pillarless solution is a bit fanciful in these times of cost and side-crash constraints. Coupe 60 hangs together with the help of a boot-consuming X-brace. "It's still possible to have pillarless, but you throw in extra tin and weight and it's ridiculously expensive."

How does it drive? Firmly. I'd peg the Coupe 60 experience right in the middle of HSV's sedans and a V8 Supercar, with a plank-stiff ride, neggy-cambered front wheels, side-exit pipes and the whiff of petrol bringing some racetrack realism. The interior is a more pure expression of sports-luxury than HSV's chintzy efforts - but riding in the Coupe 60's re-trimmed RaceTech carbonfibre seats is like a spanking session with a dominatrix.

It also drives slowly. Coupe 60 itself may not be far from reality, but that can't be said of the bespoke 21-inch tyres (245/35 front, 285/30 rear) which were hand-cut with a Holden-designed tread pattern. Anything above 40km/h could throw the rubber; stopping on the outer banking of Lang Lang's speedbowl could roll the soft sidewalls off the rims.

Then again, it might not. But neither Holden's design department nor the suit who inked the Coupe 60's $1.5m insurance policy wants to find out.

Almost certainly, we'll never get to drive a production VE Monaro. Holden's design efforts are now necessarily split between its large, rear-drive models and a new emphasis on advance design of smaller, front-drive cars, of which Cruze is an early example.

Hughes sees Coupe 60 as a glorious celebration of rear-wheel-drive proportions - "every designer in the world would like to work with the proportions that we're handed out here" - but he stresses that Coupe 60, with its blend of overt sex and enviro-tech sensibility, is very much alive in its message.

"Do we really want to give up rear-drive cars if we can make them more efficient?" he asks. "There's the challenge: for a car company to keep the dynamics of a rear-wheel-drive car while keeping it efficient and economical. If you can buy a rear-drive car that's as efficient as a smaller front-drive one, would you?"

If it's a Chevy Camaro, even a V6, we answer hell-yeah!

Camaro came from a US show car, but the finished product is as much a tribute to Holden design as it is to Holden's engineers. Production viability wasn't included in the fibreglass shell that arrived from the States.

"The show car was what we call 'cheated'," explains Hughes. "It can't be produced. It was pushed to the very limits in terms of pressings, slammed roof, overhangs, those sorts of things. The challenge was to move [key aspects of the structure], by 30mm in some areas, to make it so you can't pick it."

Hughes describes the result as "a dramatic American statement", which he clarifies as being more extrovert than the drama of Coupe 60. "It has to be," Hughes says. "When you drive on their roads over there, BMWs just disappear. You don't notice them."

A close cousin of the Coupe 60, Camaro is very much the squat, haunchy two-plus-two. It's longer in the dash-to-axle (by 75mm), shorter in the wheelbase, much shorter in the tail, wider in the track. I realised that the black Camaro SS Rallye-Sport that was staring me down, crow-like, was pure Batmobile.

The interior is certainly dramatic, from the deeply-dished, Buck Rogers steering wheel to the sweeping, amphitheatre-like instrument panel. Everything's focused on the front two occupants, though the rear is quite habitable for kids. Interior visibility beyond the B-pillar is severely restricted, but the consolation comes in the exterior-mirror view back to those hard-edged haunches.

The dynamics live up to the promise. The manual-trans SS (V8) drivetrain feels instantly familiar to anyone who's driven a recent V8 Holden/HSV product. There's a smidge of understeer and perhaps a tad more give in the overall chassis feel, but the chassis' grip and responsiveness are spectacular. I'm deeply impressed by the SS's ride, which is pock-marked only by the rumble through the 20-inch tyres ... until I step into the V6 base LS version.

It's a sweetheart by any measure. The 3.6-litre, direct-injected engine is both adequately strong in the mid-range and absolutely up for a thrashing. The six-speed Aisin manual 'box is unsurprisingly lighter and faster than the V8's six-slot Tremec, and the steering's quickness, plus the incredibly refined ride on the 18-inch 55-series tyres, make this an easy car to get in and drive fast, every day. It made me think of a Commodore SS crossed with a Nissan 370Z.

Andrew Holmes, Camaro's program engineering manager, says the philosophical shift from four-door Commodore to pony-car icon was dead easy. "Among Australian engineers who do that sort of stuff anyway, it was an opportunity for us to build a genuine sports car ... Monaro was something that came off an existing platform, there were certain constraints in place."

In today's GM, there isn't the same sort of freedom to do covert, Sunday-afternoon skunkworks projects like the one that started this whole thing 11 years ago. But Holmes points out there's a definite upside. "Back then we had a little bit more autonomy - but by the same token, there's stuff you miss out on.

"You know, it's nice to be able to go to the guy who did Corvette and the Cadillac XLR and say: 'I've got a little problem, how did you solve it on your car?' And at the same time, it's nice to have those guys all asking us stuff we know about."