Sinclair C5 computers like the hugely successful ZX81 and ZX Spectrum, an affordable electric vehicle could unleash pent-up demand for a market that did not previously exist. However, Sinclair performed no market research to ascertain whether there was actually a market for his electric vehicle; as the director of the Primary Contact advertising agency commented in January 1985, the project continued all the way to the prototype stage "purely on the convictions of Sir Clive". With Sinclair's new specifications in hand, Ogle worked on a three-wheeled design dubbed the C5, which bore similarities with the earlier three-wheeled Bond Bug – another Ogle
Clive Sinclair 1,000 a month, placing orders with suppliers for 10,000 of each component to be delivered. Sinclair wrote a book for Bernard's Publishing, "Practical transistor receivers Book 1", which appeared in January 1959. It was re-printed late that year and nine times subsequently. His practical stereo handbook was published in June 1959 and reprinted seven times over 14 years. The last book Sinclair wrote as an employee of Bernard's was "Modern Transistor Circuits for Beginners", published in May 1962. At Bernard Babani he produced 13 constructors' books. In 1961 Sinclair registered Sinclair Radionics Ltd. His original choice, "Sinclair Electronics", was taken;