Clive Sinclair 1985 owing to Sinclair's financial troubles.) The following year, he received a knighthood and formed Sinclair Vehicles Ltd. to develop electric vehicles, which resulted in the unsuccessful Sinclair C5 in 1985. In 1984, Sinclair launched the Sinclair QL computer, intended for professional users. Development of the ZX Spectrum continued with the enhanced ZX Spectrum 128 in 1985. In April 1986, Sinclair Research sold the Sinclair trademark and computer business to Amstrad for £5 million. Sinclair Research Ltd. was reduced to an R&D business and holding company, with shareholdings in several spin-off companies, formed to exploit technologies developed by the company.
Sinclair C5 production line remained closed permanently. On 19 September 1985, Sinclair Vehicles changed its name to TPD Limited, with a direct subsidiary named Sinclair Vehicles Sales Limited continuing to sell C5s. TPD only lasted until 15 October, when it was placed into receivership. The receivers announced that 4,500 C5s had been sold by Sinclair Vehicles, with another 4,500 remaining in the company's hands. £7.75 million was reportedly owed to creditors, of which £7 million was owed to Sir Clive Sinclair himself in reflection of his personal investment in the project. Hoover was not among the creditors, as Sinclair had managed to