People like to say "機車" in Taiwan when they met something make them angry. In Taiwan, there are many dirty words which be say out by people when they have bad mood.
In America, we usually heard people say "shit" when something or someone makes them angry. The word "機車" is came from a Taiwanese dirty word. This word is very dirty and impolite , it means women's organ. So some people change this dirty word to "機車" which has the same tone for first word.
We can't translate "機車" to English since the English word of "機車" is motorcycle. "機車" in Taiwan means very angry but "motorcycle" is not a emotional word. They're different words.