Despite the world of luxury motoring branching out into ever more creative niches, premium brands reserve their very best for their flagship limousines. Such cars serve two purposes: to provide the utmost pampering to the lucky few drivers (or perhaps the driven), who get to step inside; and to provide a platform for the technology that will trickle down to more affordable models in the years to come.
And so it is with the latest A8. Audi's biggest gun has long sat in the shadow of its main rivals, the Mercedes S-Class and BMW 7 Series, which have traditionally held the upper hand in terms of comfort and driver involvement. Audi has pulled out all the stops with its new model, and as you can see from the car's test score, it's a hugely impressive result.
At launch in the UK, there's just the choice of one petrol and one diesel. Both are 3.0-litre six-cylinder units, and offer 340hp and 286hp respectively. A plug-in hybrid version has already been developed and should make its way to the UK in due course. Unfortunately, the high-performance 6.0-litre W12 petrol version won't.
What is on offer, though, is the chance to boost the A8's luxury credentials, by specifying it in long-wheelbase guise. This adds 13cm between the front and rear axles - that might not sound like much, but it vastly increases the amount of legroom in the rear, to the point where the rear seats can (provided you've specified the 'rear comfort' options pack) recline to near horizontal.
Whichever model you choose, you'll get Audi's quattro four-wheel-drive system and an eight-speed automatic transmission. Both the petrol and diesel are mild hybrids, too. They won't let you run on electric power alone like a Prius, but it uses a small electric motor and lithium-ion battery to imperceptibly provide power in certain situations and boost efficiency.
Two trim levels are available. The standard A8 is well equipped, coming with most of the toys you'd expect in such an expensive luxury model. Key equipment includes adaptive air suspension, 'virtual cockpit' digital instrument display, LED headlights and electrically adjustable heated front seats.
All models also get Audi's full MMI infotainment system, which includes navigation displayed on twin displays, a DVD player, DAB radio and a host internet connected live services.
Upgrades on S-Line models are mainly stylistic, with different bumpers, side skirts and larger alloy wheels. They're further equipped with front sports seats and 'Matrix LED' headlamps, which can provide high-beam illumination without dazzling oncoming traffic.
On top of all this, buyers can significantly balloon the price of their A8 with a huge array of optional extras, most of which are organised into various packs (comfort, safety etc) based on their function. Highlights include digital TV reception, a Bang & Olufsen sound system and the rear comfort pack on long-wheelbase models, which includes electrically adjustable rear seats with integrated footrests and controls for the car's entertainment system.
There's more to come, too. Audi is primed to offer an impressive array of advanced autonomous assistance systems, which among other things, allow drivers to remotely park their car. These are largely being held back by legislation in the various markets in which the A8 is sold. Watch this space.