The A8 L W12 is rapid, agile and fun to drive as well as being extremely refined. Combined with the obvious extra rear space it’s an excellent flagship limo. However, it costs £22,000 more than the also excellent 4.2-litre TDI A8 L and is around half as economical. Try that before committing to this version.

Forget downsizing - the Audi A8 L W12 is all about space, power and prestige.

This luxury limo has a 6.3-litre engine whose 12 cylinders are arranged in a W shape. It develops a mighty 493bhp, catapulting the car to 62mph from rest in just 4.7 seconds.

The other important number is 130 - the extra length in millimetres separating the A8 L from standard versions. It’s all given to rear leg space so that pampered passengers can really stretch out.

But while the A8 L hardly lacks room, it still doesn’t have the cave-like rear spaciousness of the Mercedes S-Class.

What the A8 L does have, though, is calming refinement in spades. The best luxury cars detach occupants from the stresses of the outside world; this big Audi’s smooth ride and ability to suppress engine, wind and road noise make it a highly relaxing place to be.

However, plant the throttle and it’s instantly clear the W12 engine is a powerhouse. Smooth, yes, but still stomach churning.

For such a big car it’s surprisingly agile too, with quick steering and plenty of grip thanks to quattro four-wheel drive. Its air suspension constantly reacts to driver input and road conditions, so the car strikes a lovely balance between pothole smothering comfort and tight body control around corners.

Some may find the exterior styling too familiar - more than a hint of Audi A4 - though others will appreciate its tasteful discretion. Either way, nobody will argue with the top rate material use and build quality.

Factor in the extra space and the A8 L is a hugely appealing luxury express - regardless of where you plan to sit.