Speaking as someone who spent over forty years working in television and feature film drama in every production I was involved in the sound recordist would record separately things such as cars driving off, door slams and toilet flushes. These are known as "wild tracks" and are recorded clean without any extraneous noise which requires total silence on the location or set, they would also record the ambient noise on the location such as water flowing or wind and be then used by the editor tracklayer and dubbing mixer. If by any chance something has been overlooked it can be recreated in a foley session or found in a sound effects library which will not only offer you say a car ticking over but give you the choice of which car.
