The A0 - A1 being a European-market minicar and A2 an aluminum-bodied economy car - is a conceptual foray into the world of personalized mobility developed jointly by Technische Universität München in Germany, and Universidad Nacional Autónoma de México.
It's known as a monocycle (presumably "unicycle" sounds a little too "circus clown") and motion is granted by an electric motor that turns a single, hollow wheel that's self-stabilized and tilt-controlled. With a 9 mph top speed it doesn't have the tailgating capabilities of Audi's other products but performance should be sufficient to terrorize pedestrians. The relatively small size should allow it to slip into your regular Audi's trunk ready for that jaunt between your parking space and desk at the office.
Battery life is only an hour, which is either a good or bad thing depending on how much you like unicycles. To see the A0 concept in action, hit play on the video below.
Flippancy aside it does look quite good fun and remarkably stable. It's certainly cooler than riding a Segway, but then falling off a Segway in front of thousands of onlookers is cooler than actually riding one, so the Audi's competition isn't too fierce.
The bad news for fans of the Audi is that as a design study, the A0 is unlikely to be produced. Saves you any tough decisions...