In 1932 a farmer's wife from Gippsland, Vic. wrote a letter of complaint to Ford Australia, saying that her husband wanted a car that could carry her 'to church on Sundays and pigs to market on Mondays'. In response, a 22 year old engineer named Lewis Brandt designed and successfully pushed the concept of a passenger/load-carrying vehicle, and the first Ford 'Coupé Utility' rolled off the production line in 1934. This vehicle was a huge success, and spawned many similar cars worldwide. However, most of the overseas pickups were more truck than sedan based, and to this day, the mighty ute remains largely a unique Australian body style.
Over the years, Ford and General Motors locally manufactured ute versions of their passenger cars, and when the 'first Australian car', the Holden 48-215 (FX) was released in 1948, an FX ute was also made available. A similar thing thing happened with the XK Falcon in 1960 - a car Ford Australia found in the US and decided would be perfect for Australia (along with a ute variant of course). When Chrysler briefly set up shop and began locally producing cars, it was a foregone conclusion that they would make utes also. Apart from a few dark patches in the 80's/90's, Holden and Ford have always produced a utility based on their volume passenger car.
Today, any load carrying car too small to be a truck is called a ute (including 4WD traybacks etc), but among the ute purists, and given the spirit of Lew Brandt's original design philosophy, a real Aussie ute is one based on a passenger sedan, preferably with a seamless body-moulded tray (exceptions made for the mighty 'tonner). Fortunately, the Australian icon is still alive and well despite the influx of cheap Japanese 4WDs, and should be with us for many years to come.