Works Only When It Has To. Citroen With Economizing Stop&Start Technology. The Citroën C3 is a supermini car with a range of inline-4 engines that has been produced by the French automaker Citroën since 2002. In accordance with PSA Group policy, the C3's chassis was used for the Peugeot 1007. Many components of the C3 are the same as those of the Peugeot 206, for example the external mirrors.