The number of exhibitors grew in the second and third shows, which were held in 1939 and 1940. Despite the outbreak of World War II, the exhibitors came from Germany, Italy, United States, Protectorate of Bohemia and Moravia. Especially popular were the cars with the wood gas engines. The fourth show, planned for the May 1941, was cancelled after the German invasion of Yugoslavia, which included the heavy bombing of Belgrade, began on 6 April 1941.