When you fire-up the Audi RS6, its twin-turbo V8 engine produces the perfectly modulated burble of a modern day muscle car. Then something odd happens. A low whine fills the cabin, quickly and steadily ascending in pitch. It's the same noise you hear in a jet before the engines start, as the Auxiliary Power Unit spools up.
In reality, the RS6' air conditioning pump creates the whine. Or does it? If you so much as breathe on the go pedal, the RS6 accelerates with all the seamless, relentless resolve of a jet fighter. Give the accelerator a hard shove, and the afterburners kick in. The RS6 shifts down a cog, growls in the time-honoured V8 tradition, and blasts forwards like a Tomcat off an aircraft carrier.