Sinclair C5 Isetta, a 1960s Italian microcar. Sinclair built a full-scale mock-up of it; according to Wood Rogers, "it looked great. I specified open sides to keep the cost down and having no doors meant it escaped a lot of regulations too." The design is strikingly similar to the modern Renault Twizy electric vehicle; Wood Rogers comments that "you could put the C10 into production today and it would still look contemporary." At the time of the C5's launch, Sinclair described the C15 as having "a futuristic design with an elongated 'tear-drop' shape, a lightweight body made of self-coloured polypropylene and a
Sinclair C5 However, it imposed a number of restrictions that limited the performance of any vehicle that would qualify under the new standards. The maximum legal speed of the vehicle would be limited to only ; it could not weigh any more than , including the battery; and its motor could not be rated at any more than 250 watts. Despite these limitations, the vehicle was seen as only the first step in a series of increasingly ambitious electrical cars. Sinclair intended it to prove the viability of electric personal transport; the hope was that, just as Sinclair had found with home