일이 빠른 사람 does not mean autmobile/car.
'Automobile' is 자동차, 'car' is 차 in Korean.
I actually haven't heard of people saying "일이 빠른 사람." But there's an expression '손이 빠른 사람', meaning people who get their jobs done quickly.
With my inicial vocabulary in Korean I know that this term could confused to ppl even more if you use the tanslator meanwhile you are learning ,but the correct term is 자동차 (jadongcha) or also you can use just 차 which it means the same, and is verry common to the daily life in Korea . This is the correct term to automovil.