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
Sinclair Radionics on the NewBrain microcomputer project, which was later taken over by Newbury Laboratories. In May 1979, the NEB announced that it intended to sell Radionics' calculator and TV interests; they were bought by the ESL Bristol group (as Radionic Products Ltd.) and Binatone respectively. In July Clive Sinclair resigned with a £10,000 golden handshake. In September the NEB renamed what was left of Radionics (i.e. the scientific instrument business) as Sinclair Electronics Ltd.; in January 1980 this was changed to Thandar Electronics Ltd. As of 2008 this business continues, now called Thurlby Thandar Instruments. When it became clear that Radionics