We recently saw spy shots of a camouflaged Audi concept car doing some photography work in the heart of Berlin, Germany, and now the automaker with the four rings has revealed some preview sketches of the concept ahead of its debut next month at the 2011 Frankfurt Auto Show.

The new concept will be called the Audi Urban Concept and it’s just the latest in a long line of e-tron electric car concepts, most of which are destined for production in the not too distant future.

Audi describes the Urban Concept as a 1+1-seat, ultra-light car for congested urban spaces–available in both coupe and ‘Spyder’ convertible bodystyles.

The automaker stresses that it’s purely a concept, but with parent company Volkswagen also revealing its own 1+1 seat tandem-style concept cars over the recent years (2002 1-Liter and 2009 L1), we could just be seeing yet another iteration of a production intent platform.

The Audi Urban Concept’s development focused on the strict principles of lightweight construction, efficiency and reduction. The result is a concept car with no unnecessary weight, but also efficient drivetrain technology.

Power comes from two ‘e-tron’ electric motors, which run on a lithium-ion battery stored in the floor, and the driving range is thought to be around 40 miles.

On board there is room for two people, their position slightly staggered and sitting low to the ground. Interestingly, entry to the car is via the tailgate.

The roof is designed to be maneuverable and slides to the rear to open. The cockpit consists of carbon fiber-reinforced plastic, which integrates the undercarriage of both seats.

They measure in at 125 inches in length, 67 inches across, and sit just 47 inches in height, but the most interesting feature is a curb weight of less than 1,100 pounds.

The latest concept is believed to be a preview of the smallest vehicle from a new range of eco-focused models from Audi that will include both e-tron electrified vehicles as well as gasoline and diesel models. Like BMW’s own i sub-brand, Audi’s subdivision will be called E and will include everything from this E1 right up to the E8 electric supercar based on the R8 e-tron concept car.

More information should be revealed following the reveal of this latest concept car in Frankfurt next month, and you can get the full green take on it with GreenCarReports’ coverage. Press days for the show kick off on September 13.

This story originally appeared at Motor Authority