Audi RS4 jumped an entire generation of the Audi A4, on which it was based.
Since there was no RS version for the B6, the B7 was the second generation of the fastest A4.

The 2006 RS4 Avant was the station-wagon version of the Audi RS4 Sedan. Since there was no competitor from the BMW in that segment, the car was well received by those who were looking for an all-wheel-drive, performant premium compact station-wagon.

The car featured the big single-frame grille taken from the Audi A8 and it was extended to the lowest part of the bumper. On its sides, there were two air-scoops to cool the brakes. Inside the wide openings on the front bumper, there were the fog-lights. The flared wheel-arches were easy to spot and to differentiate the RS4 from a standard A4 Avant. To improve the car’s mass distribution, it featured aluminum front fenders and hood. Even though, the car had a hefty 1710 kg (3770 lbs), due to its large, V8 engine.
Inside, there were badges to tell about the car’s version embodied on the seats and on the steering wheel. The flat-bottom steering wheel was garnished with aluminum parts to enhance the sporty feel of the car. The carbon-fiber trims around the dashboard and on the center console left no mistake about the car’s intention of performance, not to mention that it was available only with a 6-speed manual. The rear passengers could enjoy the comfortable seats, especially from the outboard. Through the middle of the floor, there was the center tunnel needed for the all-wheel-drive system.

Under the hood, there was a naturally aspirated V8 engine. It was the last naturally aspirated Audi RS4.