Find fault in vehicle parking (4)
I believe the answer is:
carp
'find fault' is the definition.
(I've seen this before)
'vehicle parking' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'parking' becomes 'p'.
'car'+'p'='CARP'
'in' acts as a link.
(Other definitions for carp that I've seen before include "Criticise - fish" , "Fish < and beef" , "Complain like goldfish" , "Complain continually" , "Fish; nag pettily" .)