Angry motorist may give off stink! (4)
I believe the answer is:
honk
This clue is a double definition.
'angry motorist may' is the first definition.
'give off stink' is the second definition.
(Other definitions for honk that I've seen before include "Toot of a horn - cry of a goose - smell nasty" , "Toot one's horn" , "Cry of a goose - sound of a horn" , "Cry of the wild goose" .)