The first RS 4 Avant, which was derived from the Audi A4, rolled off the assembly line in spring 2000 under the direction of quattro GmbH for the first time. Audi once again cooperated with an external partner on the car’s development – Cosworth Technology Ltd. of Northampton, England, which belonged to Audi from 1998 to 2004.
The basis was the 2.7-liter twin-turbo V6 from the Audi S4. The engineers made extensive modifications to the turbochargers, the cylinder head and the exhaust system to bring the five-valve engine up to 279 kW (380 hp). A constant 440 Nm (324.53 lb-ft) of torque was available between 2,500 and 6,000 rpm. With a time of 4.9 seconds for the standard sprint and a top speed of 250 km/h (155.34 mph), the RS 4 Avant offered impressive performance. The power flowed to the quattro powertrain through a six-speed manual transmission.
Mounted behind the 18-inch wheels with 255/35-series tires were large, internally vented disc brakes. As in racing, they featured a composite design. 14 steel pins connected the steel friction ring to the aluminum cap. A four-link front axle and a double-wishbone suspension in the rear gave the powerful Avant its road-hugging character. The body was lowered 20 millimeters (0.79 in) compared with the volume model.
The body with the roof spoiler, the flared fenders and the chiseled side sills gave visual expression to the dynamics of the RS 4 Avant. Large, grille-covered inlets were carved into the powerful bumpers. The interior offered heated and leather-covered Recaro sport seats and a Bose sound system. With 6,046 units, the RS 4 Avant was an excellent seller. It was only built for just over a year, however, because the A4 on which it was based was discontinued in September 2000.