A German guy named Hanns Trippel designed it in about 1961. They estimated that they would sell like 20,000 a year but only sold just under 4000 before the company went out of business. From what i know the cars were horrible. Notoriously bad to drive on land never mind in water. Most of the cars even had some serious problems when it came to water proofing the engine, the water would get into the engine and cause it to seize up while in the water. In a move of genius the cars were sold with an oar just in case you sank
But from what I know it is the only mass produced car that could go in water although obviously you might sink..