The research in primary sources such as the personal papers of former Rolls-Royce managers and employees, together with coachbuilder records has made possible a seamless account of the whole of the history, design, manufacturing processes, and period sales analysis. Nubes Argentea’s archive is constantly increased by the acquisition of period photographs and literature from other archives, the Internet, autojumbles, and auctions, while modern pictures are taken by the author travelling all over the world, allowing him to get a complete description of every model. In every book, cars pictured are always identified by their chassis number, thanks to the meticulous analysis of every detail of the subject.