S4 Avant
Audi packs their S4 performance into the superb Avant wagon. If you crave the sports car but need the space, it's yours. However, the E-46 3-series Touring wagons, and hopefully an M3 Touring. On the grill is a visible S4 emblem. That and the special air intake design are the main ways to spot S4s, rather than plain A4s.
S4 Biturbo Engine
According to Car and Driver, the M3 engine is still better by one point, but thats a 9-10 score. The S4 is propelled by a twin turbo V6, displacing 2.7 liters and pumping 250 horsepower (the next M3 is rumored at 350:). The 30 valves apply power to either a 6-speed manual transmission or Audi/VW/Porsche's superb 5 speed Tiptronic (automatic with manual modes). As icing on the cake, the Audi Quattro all wheel drive system is standard.
S4 Sedan
The wheels on this S4 are the final way to externally locate S4 vehicles. This quick sedan is good for 157 mph, but will probably be limited to 140 or so, in compliance with Autobahn regulations.
