Quadricycle

The  was a vehicle assembled in Clara Oswald's garage by the Eleventh Doctor during The Bells of Saint John. It was never depicted on screen.

In real life
The  was the name of Henry Ford's first automobile, assembled on 4 June, 1896, in a woodshed. When it wouldn't fit out the door of the woodshed where it was assembled, Ford took an axe to the wall. At this time Ford had been married to his wife, Clara, for about 8 years.