Vehicle owner may be distressed (8)
I believe the answer is:
careworn
'distressed' is the definition.
(thesaurus)
'vehicle owner may be' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'may be' is an anagram indicator.
'owner' is an anagram of 'eworn'.
'car'+'eworn'='CAREWORN'
(Other definitions for careworn that I've seen before include "stressed" , "worn-out" , "Run down by anxiety" , "Showing signs of stress and worry" , "Tired, unhappy" .)