Motoring research has its challenges, especially when it relates to events of more than a century ago, involving a multitude of manufacturing companies, all of which have ceased to exist, and whose products have survived in astonishingly small numbers. Success is dependent upon the combined knowledge and resources of a wide group of institutions and individuals, some of whom have spent decades amassing and collating catalogues, photographs and scraps of information, all of which contribute to the creation of a coherent picture of these long extinct enterprises and their machines. Following publication of The Tricycle book, Part One, several individuals contacted Surrenden Press and offered access to their records on the Singer, Progress, Ariel, Beeston and Quadrant factories, which substantially helped with the preparation of Part Two. All contributions are welcomed and acknowledged.