Urban growth and the development of metropolitan areas are global challenging phenomena putting pressure on the development of transportation systems. In developing countries, its effects are often amplified by exponential growth and limited existing public infrastructures. Therefore, metropolitan growth is strongly linked with private motor vehicle ownership dynamics. In order to assess and quantify this statement, this paper investigates the link between socio-economical characteristics of metropolitan areas and the development of private car ownership to better explain and guide current motorization patterns in developing countries. First, the panel of analyzed metropolitan areas is presented to define the scope of this research. The final perimeter represents a diverse set of metropolitan areas with a focus on developing countries where private motor vehicles ownership dynamics seem to be the most significant. Data from up to 52 metropolitan areas have been used in selected analyses. Second, the identification of relevant indicators of private cars ownership is discussed with concerns about data availability in relation with geographical and temporal scales. This paper especially proposes to focus on metropolitan level indicators that better describe local mobility and socio-economical characteristics instead of the traditional national indicators. A consumption statistical model is applied to explore the dynamic relationship between household income distribution evolutions and private motor cars ownership and to realize general trend forecasts for a shortlist of 17 metropolitan areas. The results confirm the importance of population densities, income distribution and GMP per capita for explaining metropolitan private motorization dynamics, especially for developing countries metropolitan areas.