When the radical Mercedes-Benz F-125! hit the stage at the 2011 Frankfurt Motor Show it was (and still is) a non-working concept. The zero-emissions F125! is great, in theory, with lithium-sulphur batteries, controls via "touch, speech and hand gestures," semi-autonomous driving, three-dimensional projector-beam displays and a 1,000-kilometer range. In reality, the F125! is, well, a novel concept with massive gullwing doors.