Encouragement to have run out in vehicle (6)
I believe the answer is:
carrot
'encouragement' is the definition.
(thesaurus)
'run out in vehicle' is the wordplay.
'run out' becomes 'ro' (cricket abbreviation).
'in' is an insertion indicator.
'vehicle' becomes 'cart' (cart is a kind of vehicle).
'ro' put into 'cart' is 'CARROT'.
'to have' acts as a link.
(Other definitions for carrot that I've seen before include "veg" , "Tapering vegetable" , "Incentive (but not the stick)" , "One prov. used to encourage" , "Enticement; vegetable" .)