You don't get the usual rumbling of an idling engine, just the whisper-quiet whirl of the e-tron's motor (Audi is currently engineering an "e-tron sound" so that outsiders will be able to hear the car) and wind whizzing by.
Two-and-half-hour stints are a breeze, thanks to the surprising suppleness of the suspension, potent engine, smooth-shifting seven-speed automatic transmission and quiet interior.