This is madness. It has been 25 years since the original, and best, Audi quattro was launched and drivers were treated to their first real taste of sophisticated, all-wheel drive technology in a car, rather than a truck-like Jeep or Land Rover. Instead of doing the obvious thing and profiting from its world-class quattro technology and prowess, the Ingolstadt firm somehow left the door open for its rivals to exploit the SUV market. Big mistake. Now a quarter of a century later, Audi is making a long-overdue entry to the luxury off-road scene with the colossal Q7.

It is the longest (more than five metres), widest (almost two metres), roomiest, most powerful, fastest, best-value, highest quality and most technologically advanced premium SUV, its maker modestly says. Not only that but the car boasts “the best residual values” — quite a claim considering that the immense seven-seater does not hit UK showrooms for another six months, when it will start at a comparatively reasonable £37,285 for the standard 3.0 TDI, rising to £48,580 for the 4.2 FSI.

The smaller, cheaper diesel is the only power pack to opt for and it is predicted that 85 per cent of all buyers will do precisely that. A figure of 26.7 miles to the gallon is not bad for a car of this magnitude and 230bhp, plus a maximum speed of 135mph from the V6 3.0 turbo-diesel lump is more than adequate for real-world drivers.

Lottery winners and Barclays Premiership footballers with considerably more cash than wisdom will go for the 20.6mpg, 344bhp, 155mph V8 4.2 petrol. Even the bog standard £37,000, 3.0 TDI is comprehensively equipped with — among other things — adaptive air suspension, Tiptronic auto transmission, multifunction steering wheel, roof rails, driver’s information system, five proper and two hidden seats, rain and light sensors, 18-inch alloy wheels, cruise control and an audible parking system. You can have any colour you like as long as it is black. If you order any other paint finish, it will cost an additional £650.

Audi has a well-deserved reputation for brilliant engineering, legendary understated design, best in the (massproduced) world interiors, plus a behind-the-wheel experience that is always drama-free. With this in mind, I knew that the Q7 would not be just good but very good. And it is. The vehicle reeks of quality and the sheer size of the beast means that second-row passengers get hectares of leg room.

There is something quite opulent, almost regal, about the unapologetically overpowering Q7 package. But the company insisted on staging the car’s official launch on the desperately slow, wide, smooth, sun-drenched, traffic cop-lined roads of Arizona rather than more appropriate and revealing icy mountain passes closer to its native Germany. While these mostly straight US highways could n ot reveal any flaws in the Q7’s on-road ability, they did little to show how capable and rapid the car might be. Once off the black tarmac and on to the allegedly rough stuff for a few measly miles, there was, once again, no opportunity to push hard. Arizona’s raw deserts and mountains are perfect terrain for hardcore all-wheel drive vehicles, but the Q7’s official off-road route was a loose gravel track. The drive leading to my farmhouse would have presented more of a challenge.

But it is not the Q7’s on/off-road abilities, its price or even its late arrival at the 4 x 4 party that worries me. My leading and only real concern is that while Audi saloons, convertibles and sports cars traditionally look subtle, sporty, understated, exquisite and graceful, SUVs, by their nature, cannot. And Q7 does not.

In the cabin, under the bonnet and beneath the skin the vehicle has triumphed. Outside, its proportions look plain wrong to me and its rear-end architecture in particular is not up to the high standards we have come to expect from Audi designers. Great engineering, outstanding build quality, satisfying to drive, fair price, nice car . . . shame about the rump.

BY THE NUMBERS

HOW MUCH: £37,285 for the 3.0 turbo-diesel Standard to £48,580 for 4.2 petrol S line

HOW FAST: Diesel — 0 to 60mph in 9.1sec, 134mph; petrol — 0 to 60mph in 7.4sec, 154mph

HOW FRUGAL: Diesel — 26.7 miles to the gallon; petrol — 20.6mpg

THEY SAY: “There’s no bigger, roomier, more powerful, better value premium SUV”

WE SAY: Good to drive, great interior, price and engineering. Big bum