This year marks the 25th anniversary of Audi's quattro system, and the RS4 gets the latest generation of the four-wheel-drive layout. Previous RS models have also used all-wheel drive for maximum traction, including the twin-turbo RS6 and RS4. The first car to wear the RS badge was the RS2 Avant of 1993, which had a Porsche- modified five-cylinder engine with 315bhp. At the time it was the world's fastest car, racing from 0-30mph in 1.5 seconds.