Audi S4
Audi's quattro four-wheel-drive system was standard on the C4 S4/S6; a first-generation Torsen-based system which used the "T-1" automatically biasing centre differential (ATB) was used on vehicles equipped with manual transmissions, while a transfer box based system was used on vehicles equipped with an automatic transmission.
Audi A1
The A1 Sportback concept is a five-door hatchback based on the Audi A1 project quattro, with longer body of , 1.4-litre TFSI engine rated at at 5500 rpm and at 1600-2400 rpm, S tronic dual-clutch transmission, electric motor rated at and driving the front wheels, ESP-controlled active front differential lock, lithium-ion batteries, a two-part spoiler with a striking centre groove integrated into the rear window, Daytona Grey body colour, aerodynamically designed single-frame grille, LED three-dimensional main headlights, turbine-look air vents and air conditioning controls, drive select with dynamic and sport modes, contrasting white and red interior colour scheme, mobile phone WLAN connection, Audi drive select with efficiency mode, MacPherson front suspension and four-link independent rear suspension, 18-inch wheels with 225/35R18 tires, diameter brake discs, electromechanical steering with speed-sensitive power assistance, magneto-rheological shock absorbers from Audi R8 and Audi TT. The vehicle's acceleration is 7.9 seconds and average CO emissions are given as 92g/km. The vehicle's electric-only range is .