THE captains of industry don't tend to appreciate a flagship that lists from side to side or bumps its way through choppy waters.

It's one of the reasons why cars reserved for the chief executive or chairman have to be silky smooth - as well as ooze quality and class.

Of the models represented in this elite category few, if any, can match the peerless ride quality of the Audi A8.

There aren't many motors in which a rear seat passenger - and that of course is where the CEO usually sits - can write a letter in the traditional way with a fountain pen and paper.

Such is the magic carpet ride of the A8 however that this exercise is accomplished with consummate ease.

Of course having every conceivable snippet of information within reach of a fingertip is also essential, something guaranteed with the big Audi's Virtual Cockpit, a 12-inch digital display behind the steering wheel that looks after everything from audio and sat nav to heating and ventilation.

Selected info is also discreetly projected onto the windscreen in the driver's line of sight but without interfering with concentration on the road ahead.

And with soft leather upholstery cosseting everyone aboard, amid luxury materials and top notch fit and finish, the A8 certainly books its place among the very finest offerings in the premium arena.

This flagship saloon, which starts at £71,695 for the standard wheelbase model and £75,690 for the stretched A8 L, really is a serious tour de force.

The line-up comprises a pair of 3.0-litre V6 engines - a 340ps petrol and 286ps diesel - while there's also a more powerful 4.2-litre TDI diesel and W12 petrol model with a whopping 500ps.

All have Audi's quattro all-wheel drive and a mild hybrid set-up, which uses stored electrical power to let the car coast with the engine switched off and stay off longer at traffic lights, benefiting fuel consumption and CO2 emissions.

The A8 55 variant, so called because of Audi's naming convention whereby cars with power outputs within a specific range get a different numeric rating - is a model of outstanding merit.

Sleek, smooth and minimalist, it is beautifully refined to drive, the V6 petrol model whisper silent with instant power on tap as it flicks through the eight-speed automatic gearbox.

Air suspension is standard as the Audi irons out uneven surfaces and on the motorway it's progress is dream-like. In fact the only downside is the fuel economy - you'll be lucky to return 28 miles per gallon.

Even though standard equipment is comprehensive and includes the likes of LED headlights with high beam assist, a rear view camera, 22-way adjustable driver's seat and a 10-speaker sound system, there are still plenty of extra-cost options.

So this version had an Air Quality Pack for £540, an Audi music interface in the rear (£175), a load through hatch (£200), 4-zone automatic air con at £1,250 and a Comfort and Sound Pack for £1,695.