12. Citroen DS
Citroen has made over 1.5 million of these fantastic, highly-advanced sedans, making the DS an enormous success.(via Citroen.Org.Uk). The DS was also sold in America, where it was considered a technical marvel and had modest success on the market.
Citroen always had problems with underpowered four-cylinder engines and complicated mechanics, so US customers were pretty reserved despite all the advantages of its basic design.