Megacity all-electric vehicle is due in 2013. The model will be sold under a new sub brand of the BMW Group.

More details on the upcoming BMW Megacity (MCV) have emerged, courtesy of Autocar.

The MCV will be an all-electric car sold under a new, as of yet unnamed, sub-brand by BMW Group. The model is scheduled to be introduced in 2013 and features a new construction paradigm for BMW, consisting of a carbon fiber passenger cell coupled to an aluminum chassis.

That chassis is made of aluminium castings and twin extrusions which run front to back on the car and can be extended to make a longer wheelbase and larger versions (even a 7-seater) of the same vehicle. At the front end, the chassis also serves as a frame to attach the front suspension and steering and at the rear a cast aluminum box holds the electric motor and single-speed transmission which will power the rear wheels.

BMW may also provide a range-extended version of the MCV with a 1.0 liter, two-cylinder engine fitted under the front nose of the car.

Underneath the cabin floor is where the flat battery will be mounted, keeping it out of the way and helping distribute weight while maintaining a safer center of gravity.

There will also be no B-pillar. Instead, the MCV will have rear-hinged doors, similar to the Mini Clubman, taking advantage of the stiffer monocoque carbon fiber passenger cell and the aluminum chassis.

And since painting onto carbon fiber isn't easy, BMW is experimenting with such measures as fitting thin layers of polished aluminum to the door skins.