People visit JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

People visit JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

A vintage car is seen at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

A visitor looks at a vintage car at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

A vintage car is seen at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

People look at a vintage car at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

People look at a vintage car at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

Vintage cars are seen at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

A vintage car is seen at JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)

People visit JJ's US Car and Oldtimer Treffen in Schwechat, Austria, on Aug. 15, 2020. JJ's US Car and Oldtimer Treffen, a vintage car exhibition, was held here on Saturday. (Xinhua/Guo Chen)