AFICIONADOS of Audi's highly-acclaimed RS model range will no doubt be smiling again following the addition of a third generation RS 4 to add to the German marque's very exclusive club.

It's pushing four years now since the previous edition of the ultra-powerful, family-sized range-topper quietly slipped out of production.

But now it's back, and back with a bang. And for this the third-generation of the lightning-fast flying machine, Audi have reserved the highly-practical A4 Avant body style as its base starting point.

However, the latest estate car design is just about all the two models have in common, for the new RS 4, with its distinctive exterior design DNA with bulging wheel arches and side skirts, high-revving 4.2-litre V8 FSI engine and latest generation quattro four-wheel-drive system, is miles apart from the rest of the 38-model A4/S4 Avant range.

The newcomer is designed to give a wide range of driving styles to suit any road condition, with an adjustable drive set-up that offers Dynamic, Comfort, Individual and Auto modes, which tweak the weight of the steering, speed of the gearchange and even the noise blasting from the exhaust tail pipes to a driver's own individual taste.

Get the revs flowing and the symphony rasping out of the twin exhausts is guaranteed to get the adrenalin pumping.

The deep, throaty grunt that blasts through on the over-run imitates a sonic boom, while you will never get fed up flicking the paddles housed behind the steering wheel just to listen to the fabulous bellowing noise the car makes while under acceleration.

And how this machine accelerates. From standing to 62mph takes just 4.7 seconds and it has a top speed that can hit 174mph should you go for the higher limited speed option. However, the super-fast estate car can still return 26.4mph on the combined cycle.

As with every RS model, quattro four-wheel-drive with a rear-biased 40:60 ratio is fitted as standard, but the latest system fitted to the RS 4 gets an advanced crown-gear centre diff and sports rear differential.

Should the system detect any slide, up to 85 per cent of power can be pushed out to the rear wheels or 70 per cent to the front, while the sports differential delivers just the right amount of power between each of the rear wheels, giving the car exceptional amounts of grip no matter what road conditions are encountered.

To put the car to the test, I had the chance to drive one from Stansted Airport back to the Audi factory at Neckarsulm in Germany where the car was produced, a journey of 550 miles or so of pure heaven, blasting along along some of Europe's finest roads and Autobahns.

Every inch of the way the RS 4 was in its element. It's surprising just how quickly the miles can be swallowed up when behind the wheel of what is effectively a true supercar in sheep's clothing.

The car was shod with optional 20-inch wheels which did produce some added road noise on rougher surfaces, but not enough to make the journey in any way uncomfortable.

What I did find slightly out of my comfort zone was the optional sports front seats. Designed more for the race track than for long-distance cruising, I struggled to stay comfortable as they moulded round my body keeping me rooted in one position.

Inside the cabin you'll find the latest version of what I believe is the best designed and laid-out cockpit on the market.

The dials, switches, fixtures and fittings all scream quality and the suptle use of brushed alloy highlights around the dials, ventilation grilles and switches, along with carbon fibre inlays and black roof lining, combine to finish the RS 4 off in the style that's only fitting for a £55,000 supercar.

Reserved only for a very select few, those lucky enough to be able add a new RS 4 to their vehicle collection certainly won't be disappointed with their purchase, the only issue being having to wait until next year for their individually-built car to arrive on these shores.

£54,925

444bhp, 4,163cc, V8 petrol engine, driving all four wheels through seven-speed S tronic gearbox

174mph

: 4.7 seconds

: 26.4

41

: 249g/km

: 35%

: 3yrs/60,000 miles