Korean word '자동차' only stands for cars on roads, not rolling stocks. Instead, direct translation of Kanji to Hanja (Korean Chinese characters) '량수' would be a better choice. :D
Yes. But the original Shinagawa station’ displays show 자동차. So I just imitated it. This video is “imitating displays of Keikyu-Shinagawa station.” Sometimes, you can find the wrong spelling of Korean in the Japanese stations.