There’s a product development meeting at the headquarters of quattro GmbH, Audi’s performance-car subsidiary. The team in charge of the RS6 Avant is discussing a mid-life “refreshment” for the model, which was launched in 2013, but they’re struggling over to how to inject even greater desirability into this charismatic, two-tonne station wagon. The RS6, you see, is near legendary among petrolheads, a vast family estate car that’s so implausibly and unnecessarily rapid it can harass supercars while transporting a coffee table, a chest of drawers and a couple of retrievers in the back. 

It’s proving tough until one of the engineers pipes up. “Herr Doktor Direktor,” he says. “We know that the RS6 is the fastest station wagen in the world, that nothing can touch it performance-wise and that it has no competition. We can, of course, just leave it alone and people will still line up to buy it. But I suggest we make it more desirable and expensive – and thereby sell even more cars – by making it even more insanely fast.” 

“I like this suggestion, Herr Doktor Ingenieur!” says the product director. “Who else is in favour of your idea? All of us? Then sehr gut! We shall make the RS6 even faster!” 

Audi RS6 Avant Performance. Photo: Christiaan Hart

Audi RS6 Avant Performance. Photo: Christiaan Hart

Thus was the genesis – at least in my fevered imagination – of the RS6 Avant Performance, the uber über-wagen, an almost five-metre-long monster whose twin-turbo, 4-litre V8 produces more power than the similar-sized engine in Mercedes-AMG’s new halo sports coupe, the two-seat GTR. Perhaps even more pertinently, the Audi’s output is identical to that of Ferrari’s hard-core 458 Speciale supercar, which is an unconscionable amount of oomph for a car practical enough, as I’ve said, to lug kids, dogs and furniture – and almost big enough to have you considering giving up the apartment and moving in permanently. 

This recently arrived hyper version is additional to the existing RS6, which carries on virtually unchanged – and is slightly less costly. While a previous iteration of this wonder wagon came with the bragging rights inherent to a 571bhp, 5-litre V10, the current standard model’s V8 makes do with marginally less power, though its greater twist – 700Nm – does help cut 0-100km/h acceleration to a fraction under four seconds. 

In every respect, however, the Performance roundly trounces both it and that old 10-pot. Maximum power is raised to 597bhp (which on the metric scale translates as an even more impressive-sounding 605ps), while torque – thanks to an overboost function that’s unavailable on the regular RS6 – is increased to 750Nm, which is accessible all the way through the rev band from 1,750rpm to a staggering 6,000. These are genuinely mind-boggling numbers for a 2,000kg station wagon, and with such mighty firepower at its disposal this one can hit 100 from a standstill in a scarcely believable 3.7 seconds. Just three tenths of a second slower than a Lambo Huracán 580-2 or McLaren 570GT, two tenths off a Porsche 911 GT3 and a mere 0.1 behind the AMG GTR, it’s a testimony to the quattro all-wheel-drive system’s ability to place all that energy where it really matters: on the road. 

Audi RS6 Avant Performance. Photo: Christiaan Hart

Audi RS6 Avant Performance. Photo: Christiaan Hart

There are clear visual clues to the RS6’s potency, from the wheel arches that are extended to accommodate its massive 285/30 tyres on 21- inch rims and the bright-red brake callipers that peep out from behind the alloy spokes, to the air-gulping orifices with honeycomb grilles at the front, the flared side sills, the spoiler and diffuser at the rear and the titanium-grey door mirrors. All, however, remain relatively subtle hints, so aside from the stunning, pearl-effect Sepang blue body colour of our test car, this Avant looks pretty much like any other Audi estate – and if you’re intent on going completely under the radar I understand you can even request to have the telltale RS (as in Renn [racing] Sport) badges removed. 

It’ll be hard, though, to mask the deep V8 burble that woofles from the engine once you’ve pressed the starter button, and nigh on impossible to mute the irrepressible medley from the sports exhaust, which snaps, crackles and pops when you’re really moving. Dial in Dynamic settings on the Drive Select system, nudge the shifter on the eight-speed auto box to S mode and flatten the throttle, and the engine note becomes even more strident: a hard and furious bellow, more vintage fighter plane than large and luxurious load-carrier. 

And luxurious the Audi most certainly is. As with all cars bearing the four-ring logo the cabin is a finely wrought work of beauty that brims with all manner of standard kit. Carbon-fibre inlay adorns the centre console and dash, while the super-comfortable Alcantara-and-leather Super Sports seats feature discreet blue stitching that echoes the exterior paint job. 

Passengers front and rear get individual air-conditioning controls, there’s a superb Bose sound system with umpteen speakers, and though there’s no virtual cockpit and the retractable infotainment screen seems small (it’s worth remembering this interior has been around for almost six years now), everything is thoughtfully placed and functions intuitively. The test car’s head-up display works well, too, beaming speed and whichever other information you require onto the windscreen just below your line of sight. 

Audi RS6 Avant Performance. Photo: Christiaan Hart

Audi RS6 Avant Performance. Photo: Christiaan Hart

This classy and refined interior isn’t quite matched by the ride comfort offered by the optional Sport suspension, so unless roads are smooth as a snooker table (and as there’s little discernable trade-off in handling), choosing Comfort on the Drive Select system is the default option here – that, or sticking with the standard air set-up. I should add, however, that as the dampers do a fairly decent job of soaking up the bumps it’s never so firm as to be downright uncomfortable. 

The phenomenal grip offered by quattro all-wheel drive ensures the RS6 steadfastly maintains its trajectory no matter how much throttle you apply when exiting high-speed corners. Likewise the car’s stopping power is extraordinary – and that’s even the case without the available carbon-fibre rotors (the specifying of which, wouldn’t you just know it, raises the Performance’s governed maximum speed from 250km/h to a positively certifiable 305). I’m less enthused about the electromechanical steering, which displays some of the numbness characteristic of such mechanisms, though there’s no doubting the helm’s precision. 

No matter how many times you press the pedal to the floor, the Audi’s acceleration – which in a tightly controlled urban environment is about the only aspect of the Avant’s gargantuan performance envelope you can legitimately push to the limit – remains utterly surreal. As for the transmission, I assume there isn’t a dual-clutch unit in the Audi inventory that’s quite up to task of handling so much power, but as the eight-speed torque-converter shifts silkily and swiftly in auto mode it’s more than fit for purpose – and that’s in spite of manual changes using the paddles that can seem tardy in comparison. 

But who really wants to quibble about trivialities when the RS6 Avant Performance is so addictive, a car so monstrously powerful that even the merest brush of the accelerator delivers a kick deep in the stomach and hurls you irresistibly forward? You find yourself laughing out loud at the sheer lunacy of it all – indeed, I’m still guffawing about this four-wheeled force of nature even now, and I handed it back to Audi three days ago. I have an uncomfortable feeling, though, that I may not be grinning quite so broadly in the next few days when the first of what I fear could be several communications from the local constabulary drops into my mailbox …