I’d call it an open secret in the world of cars but for the fact that everyone knows about it: the dual-clutch transmission in the last-generation Ford Fiesta and Focus was an utter disaster. The gearboxes are plagued with problems like sudden acceleration, sputtering, and slipping into neutral at highway speed.
Source: Gizmodo – Ford Knew How Defective Its Fiesta and Focus Transmissions Were for Years: Report