The German brand says the tiny pure-electric technical studies are not descended from any previous Audi model, and that their development "is based on the strict principles of lightweight construction, efficiency and reduction".
The tiny concepts with the exposed 21-inch wheel wheels stretch 3,200mm long, 1,700mm wide and a mere 1,200mm tall. Propulsion comes courtesy of two e-tron electric motors that draw energy from a lithium-ion battery.
To keep the weight down, Audi has used a mix of carbon fibre-reinforced polymer and aluminum to construct the two models.
The Urban Sportback model features a canopy that forms part of the body and slides up and to the rear to reveal a 1+1 seat layout with the passenger positioned back and to left of the driver.
In Spyder form, the concept does away with the sliding canopy but gains a pair of doors that open up diagonally along with a lowered windshield and continuous side window area.
More information on the two studies are to be released closer to the Frankfurt Motor Show.