Vehicle engine finally getting maintenance (4)
I believe the answer is:
care
'maintenance' is the definition.
(synonyms)
'vehicle engine finally getting' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'finally' suggests the final letters.
'getting' means one lot of letters go next to another.
The last letter of 'engine' is 'e'.
'car'+'e'='CARE'
(Other definitions for care that I've seen before include "Feel concern or interest" , "Serious attention and thought" , "Caution; keeping" , "Have concern or regard" , "Caution, regard for safety" .)