1919 - 1921
John Wooler was well-known for his motorcycles, which were built by ten different companies between 1911 and 1955. In February 1919 he announced an unconventional cyclecar called the Wooler Mule. It had a 1020cc horizontally-opposed air-cooled twin, with triple belt drive to the countershaft which provided three forward speeds, and shaft drive from the countershaft to a worm gear rear axle. The rear wheels were so close together that the Mule was often referred to as a 3-wheeler.
Source: Nick Georgano / The Beaulieu Encyclopaedia of the Automobile