Built in Nuremberg, Germany, by the well-established motorcycle firm during a downturn in the two-wheeler market, this push-me-pull-you was based on a Dornier prototype and powered by a 250-cc, 14-horsepower engine, giving it a top speed of only 50 mph, assuming you had that kind of time. Its unique feature was the rear-facing bench seat, which meant passengers could watch in horror as traffic threatened to rear-end this rolling roadblock of a car. Soon it became clear — "Ach Du Lieber!" — that the Janus was a disaster, coming or going.
Source: The 50 Worst Cars of All Time - www.time.com