Mercedes AMG's hottest cars of 2015 receive a chilly reception at Australia's pinnacle of motorsport achievement

“We got as far as The Cutting and then the G-Wagen ran out of talent … so, for the time being, we won’t be using the top part of the circuit.”

Peter Hackett, top driving instructor for AMG Australia, barely believes he has to tell us this. And we can barely believe the reason why.

Germany’s best off-roader, an equivalent of the Defender and Cruiser 80-Series, has been thwarted climbing a mountain that, in any country other than Australia, would be called exactly what it is, a decent-looking but hardly outrageously large hill. And for what reason? That’s the maddest part of all … it’s something Australians don’t see a lot of. Something Kiwis don’t equate with Australia, either.

Snow. The greatest road circuit in the world, Mount Panorama at Bathurst, has disappeared beneath a fluffy blanket; the heaviest cover in 70 years, as it transpires. By 9am the sun is out but, Hackett relates, there’s still 18cm across Skyline, more than enough to stop the gloriously unhinged, epically hedonistic occasion that is the Festival of AMG in its tracks. For the next few hours, at least.

What to do? Simply hope conditions will improve. Not ascending this 862- metre summit would be a criminal waste of the talent at our disposal today, starting with co-sharers of a flavour-of-the-moment twin turbo 375kW 4.0-litre V8. The latest C63 S sedan and the GT S coupe are cars we’d expressly come to drive. There’s 30 of the first, 11 of the second, sitting powerless in the pits. In support are three examples each of the SL63 and CLS63, six E63s, two S63 coupes, plus a squadron of A45 and CLA 45 all-wheel-drive turbo fours because small can be big here, too.

That’s a very hot $13.5 million fleet being cold-shouldered by the big chill and there’s no Plan B, because we’re here on the final day of a week-long effort that has cost the brand … well, no-one’s saying, but it’s gotta be a seven-figure amount, for sure. Australia’s 6.5km Nurburgring is a top dollar place, not least because it’s only available for commercial hire for just 12 days a year.

AMG broke the ice here seven years ago but this second stint is bigger, better, bolder: More cars, more effort – AMG has arranged return daily charter flights out of Sydney and owns the town’s biggest hotel, the Rydges overlooking Conrod. The circuit has become AMG mountain, dressed in branded bunting and placards. Superstar brand ambassadors Bernd Schneider (Merc’s DTM ace) and bike racing god Mick Doohan are here commanding a battalion of AMG driving instructors. Among them V8 Supercar drivers, 2011 Bathurst winner Nick Percat and our own Chris Pither included.

Obviously such a huge effort isn’t simply for the amusement of a couple of Kiwi journalists. In the main it’s an owner event; each one paying $3500 (chicken feed obviously, because the exercise is sold out within a week). I reckon they’ve put $980,000 into the local bank of Benz – potentially enough to cover this event’s incidentals.

A morning spent undertaking skills activities around the start-finish area is good fun, but hardly going to rate as money well-spent by the big noters; there’s obvious relief when the lunch break also brings good news: The track administration has re-opened the full circuit, but with the caveat that we need to keep speed down to 80kmh over the top part, at least until a dry line forms. Funnily, the only oopsie of the day comes at the other end of the place, at a place we’ve been playing around all morning – and, yes, it was a fellow writer, not an owner, who got it all wrong at The Chase. Fortunately, his muck-up only results in the CLA 45 he’s driving getting muddy.

We’re supposed to rotate through a wide assortment of cars in stints of two laps, but our desire to prioritise the C63 S and GT S is recognised. Three stints in the first, two in the second, is better than actual owners get, yet it’s also barely enough, so overwhelming is their narcotic effect.

Gosh, the GT S – a car AMG has created to take on no less than Porsche’s 911 - feels fantastic here: Everything’s fast down Conrod and there’s nothing here that doesn’t make mundane drivers feel like superstars, but nothing sounds a ferociously ‘right’ nor reaches the 250kmh limit as quickly as the sports two-seater. It’s also the ace handler; deft, light to the touch, superbly balanced and brilliantly stable when you’re asking everything of the ceramic brakes.

The C63 is hardly relegated to the bench; it also provides powerful positive impression. A 0-100kmh time of just four seconds is impressive as heck for a sedan and an extra 50Nm extra torque over that from the GT S tune also offsets the weight imbalance over the coupe.

How will these cars feel on the road? In one way, we’ve already discovered an answer because, for the greater part of the year, Mt Panorama is just that: A public road. And yet, of course, it’s not like any other public road I’ve ever been on.

Forget the ice. The heat is on.