The Japanese word for car is kuruma and jidousha. Karuma means car and the word is commonly used in informal settings while jidousha means automobile and is more suited for formal settings.
The kanji for car
The kanji for kuruma is 車 which simply means car but the kanji for the more formal jidousha is 自動車. The two uses the same kanji character except that the formal jidousha has two additional characters that precedes it – namely 自 and 動.
The first of these additional characters – 自 – is a prefix that means ‘self’ and the second character – 動 – is an expression for the act of moving. So the word jidousha basically translates to self-moving car.