The Wankel is a single-rotor unit of 254cc and runs at a constant 5000rpm to extend the car's range to 130 miles

The A1 is Audi's latest of a line in e-tron concepts, and is really fascinating because it makes a nod to a sometimes inglorious past in the shape of the NSU Ro80 - one of the most forward looking cars of the 1960s. It's powered by a compact Wankel rotary engine/generator to maintain charge in its battery pack.

The lithium ion battery pack delivers about 30 miles a charge and weighs a mere 330lb. The electric motor delivers 61 horsepower and gives the A1 a 0-60 time of just under 10 seconds. The Wankel is a single-rotor unit of 254cc and runs at a constant 5000rpm to extend the car's range to 130 miles - it would be more but the fuel tank is only three gallons!

Audi has real Wankel form - the first ever production car with a Wankel rotary engine was introduced by NSU back in 1964. NSU later merged with Auto Union, which also included Audi, the sole surviving brand of the group.