French researchers are concerned that consumer demand for hybrid cars, fueled by advertising and PR, is slowing down the development of genuinely sustainable green auto technologies. Their report, Hybrid Vehicles: A Temporary Step [3], states that "There is a general convergence of strategies toward promoting hybrid vehicles as the mid-term solution to very low-emissions and high-mileage vehicles ... Such a convergence is based more on customer perception triggered by very clever marketing and communications campaigns than on pure rational scientific arguments and may result in the need for any manufacturer operating in the USA to have a hybrid electric vehicle in its model range in order to survive." Technologies that may be taking a back seat as a result include hydrogen fuel cell electric vehicles. Nearly 24,000 hybrid vehicles were sold in the U.S. in January 2008.