The Iter-Auto was a GPS navigation unit developed for autombiles by the Italian Touring Club, ca.1930. The company was located at Via Due Macelli, 31, Roma, Italia. The Iter-Auto utilized pre-printed rolls of paper with routes to and from major destinations. It was to be connected to the car's odometer and, as the car progressed en route, the map would scroll accordingly. Problems would arise, however, if the driver ventured off one of the predetermined routes or drove in reverse.
Other than the Italian made Iter Auto, a similar American device was patented in 1921 by John J. Bovy which he called a "Map Holder." Bovy's design required the driver to advance the map scrolls manually. Another devise, "The Plus Four Wristlet Route Indicator" of 1927, was operated manually like Bovy's design and had predetermined routes on scrolls like the Iter Auto, but it was meant to be worn on the wrist like a watch.
Please contact me if you have any of these early route finders for sale.