Appreciated Greek character’s vehicle (4)
I believe the answer is:
taxi
'vehicle' is the definition.
(taxi is a kind of vehicle)
'appreciated greek character's' is the wordplay.
'appreciated' becomes 'ta' (I've seen this in other clues).
'greek character' becomes 'xi' (letter from the Greek alphabet).
'ta'+'xi'='TAXI'
(Other definitions for taxi that I've seen before include "Car for hire" , "Move along a runway" , "I hail you!" , "Motor vehicle for hire with driver" , "Motor cab" .)