Meet the next member of Audi's e-tron family, the A1 e-tron.
The Frankfurt car was a high-performance sports vehicle, with electic motors on all four wheels.
The Detroit car was a lightweight, compact two seater with two electric motors on the rear axle.
The A1 e-tron is a classy three-door four-seater powered by lithium-ion batteries and a small combustion engine.
It can go for 31 miles on electric power alone, and that is extended by a further 124 miles with the aid of the petrol engine.
The car always drives on electric power - the engine recharges the battery and doesn't drive the wheels.
This means the car is capable of an incredible 148.7mpg and emits 44g/km of carbon dioxide.
The 100bhp A1 e-tron has a top speed in excess of 80mph and can go from 0-62mpg in just over 10 seconds.
A fully depleted battery can be recharged in approximately three hours from the 380 volt grid. A display immediately adjacent to the plug-in connection shows the current charge status and the charging time remaining.
The best bit is that we could see a full production version of this Audi e-tron in around 18 months. What's not so good is that the glass panel in the boot, where you can see some of the technical wizardry (the range extender control unit), won't be in the production car.**