Audi's e-tron electric supercar concept has already been through two iterations--or, rather, one. With two different-colored R8-styled show cars, Audi hit the Frankfurt and Los Angeles Auto Shows hard. Now they've brought a third color and a new more cab-rearward layout to the car.

With the mid-engine proportions gone--this is an electric car, after all, and with the motors mounted inboard of two wheels, the powertrain is highly reconfigurable--the e-tron looks more like a classic front-engined sports coupe. It is also a very compact design, with a wheelbase of just 95.67 inches--that's 8.66 inches shorter than the R8.

Unlike the previous e-tron concepts, the latest uses two electric motors instead of four, driving the rear axle. By only driving the rear wheels, the new e-tron concept is able to maintain Audi's desired weight distribution of 40:60 front:rear despite looking like a front-engine (and therefore front-heavy, or at least 50:50) car. The battery unit sits just in front of the rear wheels, and checks in at a hefty 879 pounds.

Styling, aside from the different proportions, follows essentially in lock step with previous e-tron concepts, including the trapezoidal grille, LED headlights and taillights, and generally high-tech, sweeping curves terminated in crisp edges.

To help keep weight down and therefore maximize range of the battery pack, the body's structure is made with Audi's Space Frame (ASF) technology, which combines aluminum and carbon fiber reinforced composites. The high-tech materials allow the lightweight structure to maintain the rigidity necessary without the bulk of steel. Total curb weight of the new e-tron: 2,976 pounds.

Performance is good, too, at 5.9 seconds 0-62 mph and 37-75 mph in just 5.1 seconds, meaning passing should be a breeze as well. This is slightly slower than the Frankfurt show car's 4.8-second 0-60 mph time and 4.1-second 37-75 mph run, perhaps hinting that Audi has begun tuning the power delivery more for range than outright performance. Top speed is electronically limited to 124 mph and range is a moderate 155 miles.

Audi promises that the car has precise and nimble handling, thanks in part to its advanced chassis and weight layout, but also to the electromechanical assisted direct rack-and-pinion steering system, which provides more feedback than alternatives. Nineteen-inch wheels with 35 spokes and a unique blue color also grace the show car.

Though it's not yet known which version of the e-tron concept will make production, the e-tron has already been confirmed for 2012.

[Audi]