Beetle -- vehicle crushed by wrecker (6)
I believe the answer is:
scarab
'beetle' is the definition.
(I know that scarab is a type of dung beetle)
'vehicle crushed by wrecker' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'crushed by' indicates putting letters inside.
'wrecker' becomes 'sab' (I've seen this before).
'car' placed inside 'sab' is 'SCARAB'.
(Other definitions for scarab that I've seen before include "Holy beetle" , "divine creature" , "Beetle, sacred to the ancient Egyptians" , "Beetle considered divine by ancient Egyptians" , "Old abuse" .)