Sighed with car spewing exhaust? (9)
I believe the answer is:
discharge
'exhaust?' is the definition.
(I know that exhaust can be written as discharge)
'sighed with car spewing' is the wordplay.
'with' says to put letters next to each other.
'spewing' indicates an anagram (letters spewed about).
'sighed' put after 'car' is 'carsighed'.
'carsighed' with letters rearranged gives 'DISCHARGE'.
(Other definitions for discharge that I've seen before include "cashier" , "meet" , "Fire (a gun); release from custody" , "Dismiss (from a job)" , "Performance" .)