The Dongfeng (东风, East Wind) CA71 was China's first passenger car, manufactured by First Auto Works in Changchun. Twenty to thirty CA71's were made. The first one, with license plate 2-42406 (like the CA71 on this poster), was shown to Mao and the other leaders in Beijing in May 1958.
See: chinacarhistory.com/2018/04/19/the-first-auto-works-dongfeng-ca71-was-chinas-first-car/

This scene could very well take place in Xi'an, with the dome of the State Guesthouse and the Drum and Bell Towers in the background, but we are not sure.