To change auto parts in a dream, means, in reality you have to perform "dirty work", which will become an indispensable condition for achieving the set goals. In the case when you dream that you have extra parts left after repairing the car, in reality you, unconsciously, have offended the person who is dear to you. If you dream that you buy or choose new spare parts for your car, such a dream should be seen as a warning not to commit rash actions.