ON paper it sounds a daft idea; make a car less practical and charge more for it.

Or take a handsome two-door coupe and compromise the lines with another pair of openings for access to the back seats, where you'll find less room than in cheaper versions.

That's what happened eight years ago when Audi produced its first A5 with four doors under a mostly coupe-like roofline.

Car buyers loved it, and hang the extra expense or lessened practicality. This was a car you enjoyed for the way it dripped style even before you slipped behind the wheel.

Now comes a new version, a little longer but narrower and a bit roomier but lighter and available with lots of clever technology as standard or - it's an Audi, after all - at extra cost.

The new A5 range starts at £33,050 for the 2.0-litre diesel Sportback SE ultra with 190 horsepower and a six-speed manual gearbox or £34,580 if you choose the seven-speed automatic version.

That means this four-door, five seat A5 with easy hatchback boot entry is the same price as the two-door, four seat A5 Coupe with smaller, conventional boot opening. That, in Audi terms, looks a bit of a bargain.

Move to better equipped SE trim and prices begin at £34,950 with the same diesel power. Petrol versions arrive with 252 horses from £39,575 and there's a 3.0 litre diesel at £39,725.

Lots of Audi buyers opt for S line trim because it adds a sporting edge to the look of their cars.

With the A5 Sportback this version kicks off at £35,915 while at the top of the pile you'll find the 155mph £46,015 S5 quattro. You'd guess an even quicker and dearer RS version is waiting in the wings.

The S5, as well as UK-bound petrol and 3.0 diesel versions, is fitted with Audi's all-wheel drive quattro system that some 19 per cent of all A5 buyers are expected to choose.

Every version of the new A5 Sportback has xenon (SE and Sport) or LED headlights (S line) and leather trim with heated front seats, satellite navigation with seven inch colour monitor, front and rear parking sensors, powered tailgate and city safety system that brakes for you if you don't spot a potential collision ahead.

Tasty options are an Audi speciality and there are enough on offer to tempt a raid on the piggy bank, from an upgraded sat nav (£550), virtual cockpit (£275) that puts a big colour screen where the conventional instruments usually live, to a head up display for £900.

For precisely no extra cash Audi will replace the standard 40 litre fuel tank on diesel models with a 54 litre one and deliver your new car without its engine related badge on the boot (so others may think you're in a bigger engined car, perhaps).

A constant rumble from owners of previous edition A5 models was the harsh ride, especially on our awful UK road surfaces. Well, complain no more. The new A5 rides perfectly nicely, with an appropriate hint of sporty firmness but an ever present ability to absorb the worst bumps.

It also moves along well even with the least powerful diesel engine doing the work - pulling smoothly via the automatic gearbox that suits the long distance strider this car surely will become with its mostly business based users.

Driven with modest verve the 2.0 diesel showed 43mpg on its trip readout - miles away from the 68.9mpg claimed in the unrealistic official test but a comforting figure anyway.

The 2.0 litre petrol A5 felt faster - but not by that much - and no quieter than the diesel. It's 30mpg figure might be improved by gentler use, but then you wonder why you'd have bought the quicker car in the first place.

Continuing the practical theme, the A5's boot is huge and easily expanded by folding the rear seatback. Rear seat passengers will find enough legroom for a six-footer and just enough headroom - but the sloping roofline does make entry and exit harder than in a saloon equivalent.

But then, an A5 buyer is going to consider that a tiny demerit in a car that looks this good.