Mobilgas run -- girl drivers, 1957
Supplementary material continues: "Drivers of run cars, both men and women, are selected by the entrants, and the sponsoring General Petroleum Corporation has no jurisdiction over who shall be selected. A car may be entered in the run by a manufacturer, a motor car dealer association or a private owner. The car must be a brand new 1957 four-door sedan or a two-door or four-door hardtop model, which shall be selected at random by USAC officials. The 1957 Nobilgas Economy Run will be held April 14-18 and will go from Los Angeles to Sun Valley, Idaho, with three overnight stops. The drivers will encounter, in four days, all the problems of traffic and open road driving, all the variations in weather, altitudes, and road conditions which an ordinary driver encounters in a year".