KEY POINTS:
Introducing a 7.0-litre sedan seems mad when fuel prices are rising, let alone a $194,500 Holden during a credit crunch. But forget the timing - I couldn't help but admire the HSV W427's over-the-top persona.
Its engine and transmission come courtesy of Corvette, the body's donated by Holden, the ingredients aren't new. The finished dish is.
This 7.0-litre V8 engine delivers the goods via a new, high-strength, limited-slip diff; a new, high-strength clutch; and a new, beefy T6060 six-speed manual transmission that's stronger and offers better shift feel. There's a three-year 100,000km warranty on this stuff and HSV has to be sure it works.
Even the wheels are a special design and they must be - to fit over the mass-ive brakes.
Everything's built to pander to the main event - that mighty engine.
Holden's general manager of sales, Darren Bowler, says: "We set out to build Australia's fastest accelerating car." HSV engineering manager Joel Stoddart calls it "our best-handling car". And supercar ace Greg Murphy? "Jesus, what have you done? That shouldn't be legal."
This W427 goes like a cut cat, yet handles like nothing this big has a right to.
It sounds fantastic, too - a deep, gut-stirring thrumming idle hints at what's on offer. Accelerate and active bi-modal mufflers release the full glory of a big V8 on max attack.
A sedate approach is rewarded by surprisingly little tyre, wind or engine noise and an impressively supple ride.
In track mode there's that feral roar as the wind tunnel up front channels air to the mighty beast. Select "track" on the MRC suspension for firm response and she squats and goes, there's little body roll and just enough hip-sway to ease you around bends.
Testament to this car's skill is Murphy's fast lap of the Lang Lang test track's ride and handling loop.
He cornered 30km/h faster than he's gone there before, and topped 268 on the speed bowl while still pulling in fifth gear.
Thankfully the ESP is subtle enough you barely notice the intervention.
Buying a car with a 17 litres/100km claimed thirst seems insane.
But in reality, it's not that bad. It measured 26.3 litres/100km after an hour going around Lang Lang, but that's hardly real-world driving.
We tallied 15.7 through Melbourne and 12.6 at our destination.
Unless your commute sticks to the city rush hour, your fuel bill should match your neighbour's SUV.
Monster-engined sedans are an endangered species and this one will be built in limited numbers - with about seven here out of 427 built.
However impressive or unusual it is, your fellow execs won't see the W427 as the BMW-Audi-Merc competitor HSV imagines, while the uninitiated will just think it's a very expensive Commodore, and apart from the red leather the cabin will confirm it.
You may know better, but do you want to pay this much for something only aficionados will understand?
