Background: Introduced in the late 1990s, the B5-generation Audi S4 was the high-performance derivative of the successful A4 range and continued Audi's established tradition of combining strong performance with quattro four-wheel drive and understated styling.

At its heart was a 2.7-litre, 30-valve V6 equipped with twin turbochargers, producing 265PS in standard European specification.

Power was delivered through Audi's quattro permanent four-wheel-drive system, giving the S4 the all-weather ability that had become closely associated with the marque's performance models.

Available as both a four-door saloon and five-door Avant, the S4 offered considerable performance without sacrificing the everyday usability of the regular A4 and was particularly effective in this respect, combining the performance drivetrain of the S4 with the additional practicality of an estate body.

Visually, the B5 S4 remained relatively restrained, with its deeper bumpers, discreet badging and larger wheels...