The A2 Concept is powered by an electric motor that delivers 60kW and 160Nm of torque to the front wheels in regular driving, with the ability to produce 85kW and 270Nm when needed.
Energy is provided by a 31kWh lithium-ion battery, with 24kWh of that made available to the electric motor. Audi promises a driving range of around 200km off one charge, putting the A2 into the higher-range end of electric vehicles.
Audi has also made the most of the weight-saving potential, using lightweight materials throughout - and even doing away with a functioning bonnet. All of this has given the A2 a kerb weight of just 1150kg, and most of that is in the battery packs.
Despite its name, the five-door A2 concept is even smaller than Audi's three-door A1 light car, measuring around 150mm and 100m shorter and narrower.
The five-door A2 is nevertheless designed to seat four people in comfort, switching the usual bench configuration in the rear for a pair of single seats.
Other neat motor-show features include internet connectivity, electric "by wire" steering and braking, and a rear foglight that projects a warning symbol onto the road behind the vehicle.
Audi describes the A2 as a technology study, but with Volkswagen's Up! city car bound for showrooms, including an all-electric version, a production future for the A2 could be on the cards.