the "NSU" name more frequently in the public eye, confusion between "NSU-Fiat" and "NSU Werke" became more frequent among the general public which also affected business professionals with whom the businesses had dealings. The 1950s found NSU Werke's General Director, Dr. von Heydekampf, complaining that customers were being deceived ("grobe Kundentäuschung") because Fiat Germany were using the NSU-Fiat name to exploit the glory of the racing successes and speed records of the NSU motorbikes. Re-entry into automobiles In 1955 it was reported that the motorbike manufacturer NSU Werke were planning to produce a passenger car in the "approximately 400cc" class and proposed to badge the little car simply as an "NSU". This seemed likely to create even more confusion in the market place affecting Fiat's smaller "NSU-Fiat"s based on the Fiat 600, already produced in Turin since 1955 and scheduled for imminent launch as a Heilbronn produced model (with the still smaller Fiat 500 already in the development pipeline). The Heilbronn built Fiat 600 was duly launched in 1956, but because of the dispute it was badged not as an NSU-Fiat but as the "Jagst" (shortly thereafter lengthened to "Neckar-Jagst") while one class up, the new Heilbronn built Fiat 1100 also introduced in 1956 was advertised as the "Neckar". The NSU offering, when it appeared on the market in 1958 as the NSU Prinz would indeed compete in the same market segment as the baby Fiats. NSU brand dispute Acrimony had mounted, involving robust exchanges of lawyers' letters, and legal hearings ensued. Arguments centred on what had been agreed about rights to the "NSU" name and, in particular, whether an arguably informal letter dated 5 January 1929 on the subject had long-standing contractual force. The judge decided that the 1929 letter could not have the contractual force necessary to bind the parties over use of the "NSU" name, because of a danger that its effect, if valid, would be to damage marketplace competition and thereby run counter to the public interest. The Fiat licensee therefore felt obliged, in 1957, to rebrand all its Heilbronn assembled cars: NSU-Fiat badged cars became Neckars. Fiat-designed models branded as Neckars Neckar was in the late 1950s producing fewer than 25,000 vehicles a year, Fiat 500 (Neckar Weinsberg), 600 (Neckar Jagst) and 1100 (Neckar Europa) slightly modified, often more luxurious and sporty than the Fiats produced in Turin. The launch of the Fiat 1500 in