BMW's i3 has four wheels. Otherwise, it shares so little with cars as we've known them that automotive archeologists of tomorrow will figure there had to be some developmental step, some missing link between the stock of model-year 2014 and this electrically driven Bimmer.
First, there's the so-called "skateboard" chassis. While a few concept cars have showcased this architecture over the past decade, this is its first production application. Here, the welded-aluminum structure, what BMW calls a "Drive module," supports the battery, steering, suspension, and mid-mounted electric motor. Aside from the steel rear-suspension links, most of the chassis components are aluminum. Atop that sits the "Life module," which you or I would just call the cabin. Its structure is molded carbon fiber, the body panels are thermoplastic, and the dash…