A British man walks up to an Audi engineer in 1994 and ask’s ‘What do you get if you cross an estate with a supercar?’

The German with a typical display of Teutonic humour replies ‘Hold on ze one tick Herr Englander, I shall go unt find out.’

The response is the worst punch-line to a joke ever created but produced one of the finest Audi’s ever made and started the marque’s RS programme. Those German’s might be rubbish at being funny but they are remarkably good at building cars.

Back in the present day (and reality), and today’s version – the RS4 Avant – is built under the same premise. Audi take a standard family estate and fit it with the sort of power and cornering ability that would make a Porsche sit up and take notice.

Because of this, getting into the RS4 Avant is extremely similar to climbing into a standard A4 Avant, though with friendlier chairs.

Those front chairs hug the occupant with a relish to rival your favourite Aunt and will hold you in place through the bends through thick or thin. There are flashes of RS Quattro about the cabin such as the flat bottomed steering wheel and ‘RS’ badges in the dials, but largely, anyone who drives a current Audi model would feel right at home in the RS4 Avant.

The interior is well appointed – and well it should be for the £55,525 asking price – and solidly built if a little dull to look at. There is plenty of leg space in the rear and a practical boot – simply because the normal A4 Avant has all of these things and it is a fairly practical car.

What sets the RS4 Avant apart is the rest of the car. There are 19 inch wheels for starters and they are wrapped in very wide tyres. The wheels are connected to a suspension system that sits 20mm lower than on a standard A4 and behind them are housed some considerably sized brake disks.

To cover all of this up and make it all road legal, the RS4 has wheel arches that can reasonably be described as ‘meaty’ and to complete the RS4 styling set-up, the front and rear bumpers get a deeper radiator grille and large expanse of diffuser respectively.

The result is a car that looks like a menacing Swedish design study – crisp, clean, with a hint of Bauhaus about it but wide with air vents large enough to suck in small dogs. I rather like it and prefer my cars to be understated rather than shouty and the RS school of design keeps everything about as understated as a 450bhp car can be.

Ah yes, the engine. Those 450 horses are extracted from a twin-turbocharged V8 petrol which also generates 317 lb ft of torque. Those figures will propel the RS4 Avant from 0-62mph in just 4.7 seconds and on to an electronically limited top speed of 155mph.

It is the in-gear acceleration that really impresses though. Plant your foot in almost any gear and the turbos spool up quickly to shove you into the back of your seat.

The engine revs up to a glorious 8,500rpm which is when it really begins to wail and sound spine tingling and the best thing about it is that the Audi almost enjoys being thrashed.

The seven-speed DSG gearbox responds quickly and fires the gearchanges at you, keeping the power delivery smooth and almost uninterrupted. It will even blip the throttle deliciously as you downchange to give you the full racing car experience.

Put the RS4 Avant into a bend like a race car and you will be surprised at just how much grip there is available, even when considering the Audi has a superb Quattro four-wheel drive system.

It doesn’t seem to matter whether it’s dry, wet or probably even icy, the RS4 Avant grips and goes – giving a whiff of understeer when the driver is really getting silly.

That driver will really have to be gunning it though as the level of grip is so high, many will never reach the RS4 Avant’s handling limits. The feedback available from the handling is good too, allowing you to feel your way into a corner with confidence and then power out smoothly.

The best thing about the RS4 Avant is that, despite being ferociously fast, it is practical, usable around town and quite happy to potter over speed bumps or creeping into parking spaces.

It really is a jack-of-all-trades and a master of most. The ride is stiff to allow for the epic levels of speed available and is therefore a little uncomfortable over a rough road but you have to make sacrifices somewhere and the suspension set-up is extremely flexible. If you wanted a family car and a supercar, yet only had the money for one and a half of them, the Audi RS4 Avant is the perfect car for you, allowing you to own a workhorse capable of winning the Grand National.