We barely got started blogging about it, and now BMW is already taking the fun out of the speculation. The mysterious car with the front end of last year’s Vision EfficientDynamics concept and the rear of the outgoing 6-series will be built—predictably, without the retro butt.

Journalists got the opportunity to ride in a prototype today at an event in Leipzig, Germany. The two-door coupe is being developed for a market launch in late 2013 and will cost far less than the all-electric Audi e-tron or the Mercedes-Benz SLS AMG E-Cell.

"We began defining our electric-vehicle architecture five years ago," says BMW engineer Philip Koehn. "In this sports car, driver and passengers will sit 12 inches lower than in our Megacity vehicle." How? In the sports car, the batteries will be placed between the seats, while the Megacity vehicle’s will be sandwiched between the floor and the bottom of the car. The car you see here is just 48.8 inches high.

There are two electric motors. One lives up front (110 hp, 166 lb-ft) and the other (52 hp, 155 lb-ft) is coupled with a 161-hp, 214-lb-ft, 1.5-liter, three-cylinder turbo-diesel at the rear axle—total system power is 323 hp. The 0-to-62-mph dash is estimated at 4.8 seconds, and top speed is governed to 155 mph. The battery pack, which will be supplied by Samsung, is made up of 98 lithium-polymer cells, which allow the all-wheel-drive car to travel 30 miles on electricity alone. With its 6.3-gallon tank and a fully charged battery, it will supposedly go for 435 miles before you need to refuel or plug in. For series production, we suspect the diesel will be replaced by a less efficient gasoline engine to suit the tastes of U.S. and Asian customers (and, even more important, regulators).

Perhaps the three-cylinder diesel won't come to the U.S., but BMW is betting on downsized engines. "Here, we have the opportunity to show a truly modern technological approach," says Koehn. "In this concept, we combined everything that makes sense from a technological point of view." Indeed, a three-cylinder makes sense, but we're not so sure about the consumer perception of such an engine, and while a three-cylinder can sound pretty sporty, this one doesn't. Acceleration, on the other hand, is pretty impressive—no wonder, given this car's curb weight of about 3100 pounds, made possible by a carbon-fiber passenger cell and aluminum parts to support the powertrain.

This concept takes off silently but moves rapidly as soon as the internal-combustion engine comes alive. It's a new, artificial kind of sporty driving, but at a projected fuel economy of 63 mpg in the European cycle, we may be willing to compromise. As the hybrid nears its top speed, the electric motors switch off. Thanks to a claimed aerodynamic-drag coefficient of 0.22, this 2+2's lofty top speed is possible even with just the 161-hp diesel motivating it—and we hear the series-production engine could be even more powerful. BMW's driving strategy: "We definitely want to facilitate purely electric driving at city speeds, up to 40 mph," says Koehn. "Around 45, maybe 50 mph, the internal-combustion engine would take over."

BMW, by the way, claims that 30 miles of electric driving is enough: "We discovered with the Mini E that there was virtually no range anxiety. Batteries weren't even charged every night." For both upcoming electrified BMWs, interior climate management—including insulation to keep it warm in the winter—is a key to increasing range, as heating and air conditioning suck up huge amounts of energy. "Nobody will ventilate an energy-efficient house six times a day," explains Koehn.

The styling is polarizing, to say the least, but we like the daring and innovative approach. The front end gives you a good glimpse of the new face of BMW cars. If you thought the brand’s design was going to get more conservative after Chris Bangle's departure, you were clearly mistaken.