Four years ago the top specification Audi A8, the S8, had a list price of about £62,000. Today, with 50,000 miles on the clock, it changes hands at auction for less than £16,000 — a loss of £46,000, around 75% of its value. But that’s great news if you want one second-hand.

Introduced in August 1994, the car came with a V6 2.8 litre engine producing 173bhp, or a 300bhp 4.2 litre V8. Cosmetically, the cars were very similar, but under the skin they were quite different. With its permanent quattro four-wheel drive, the 4.2 was unique among luxury cars, while the 2.8 was a distinctly “un-luxury” car with front-wheel drive.

The following year Audi added another front-wheel-drive model, the 230bhp 3.7 litre V8. And finally in 1997 came the 330bhp S8. Lighter than most of its competitors, the S8 had the potential for greatness, but as it cost £10,000 more than a 4.2 quattro Sport, for only an extra 30bhp, sales proved disappointing.

All engine sizes offer the buyer a choice of standard or Sport variants. Sport models come with larger alloys, lowered suspension and electric memory seats. Second-hand Sports command a £1,000 premium but try before you buy, as the stiffer suspension is not to everyone’s taste.

On the road the A8 feels sure-footed and nimble and is particularly stable at high speed, while quattro models provide enormous reassurance. But Audi steering tends to lack feel, and the A8’s is no exception.

Accommodation inside an A8 is among the best in class with excellent head, leg and shoulder room. The boot will comfortably swallow a couple of sets of golf clubs plus your weekend bags. And in case that’s not enough, since 1999 Audi has offered a long-wheelbase version of the 4.2, which adds a further 5in to the rear legroom.

Build quality is one of the A8’s trump cards, and even on early cars you will be struck by the finish, the high-grade wood, leather and plastics combining to produce an environment as luxurious as anything this side of a Maybach.

Exterior condition must be excellent; repairing even minor damage to the aluminium body is expensive and must be carried out by a body shop specialising in aluminium repair. So if you’re buying a car privately, adjust the price if you spot bodywork damage.

The big Audi underwent some major modifications as part of the 2000 model-year changes. All models gained the quattro system as standard and engine power increased. The biggest power hike was for the S8, which with its extra 30bhp taking it to 360bhp, and a simultaneous £10,500 price reduction, became the car it always should have been.

Servicing on all models is at variable intervals based on driving conditions, but expect to see a dealer once a year or every 10,000 miles. Because of its aluminium body, insurance tends to be slightly higher, so shop around for quotes.

Seats Electric memory seats on Sport models very desirable

Interior trim Fantastic build quality so high-mileage cars should still look fresh

Air-conditioning Standard on all cars and can be adjusted to different temperatures for driver and passengers

Mobile phones Aluminium body and double glazing make for poor phone signal quality. Phone aerials should not be attached to the body; Audi's own kit has an aerial mounted inside the bumper

Bodywork Aluminium construction means that contact with inappropriate tools during repair results in 'contact corrosion'

Chrome-effect trims Made from aluminium and if cleaned incorrectly can turn milky white

Towbar Must be Audi approved item or can trigger 'contact corrosion'

Tyres, brakes and steering rack All prone to heavy wear on V8 and quattro models

Satellite navigation Two versions - the "Nav plus" system includes TV and colour screen

Transmission Check 4x4 transmission system for noise and oil leaks

Wheels 20in wheels available since 2001 make car look great though ride can be harsh

• Audi A8 4.2 quattro Sport, 1999 T-reg with 30,000 miles and full service history. Pay £18,395 at a dealer, £16,250 from a private seller.

Deduct £1,000 for non Sport models. 3.7 worth £2,000 less than equivalent 4.2. Source: estimates based on confidential CAP black book prices. 'Trade' is what a dealer would pay to buy your car; 'retail' is what you would pay a dealer

Source: estimates based on confidential CAP black book prices. ‘Trade’ is what a dealer would pay to buy your car; ‘Retail’ is what you would pay a dealer

Alternatives

Figures based on CAP December 2005 edition

 © Bumper Media Limited Mach 2007