Mark circling yard in eg NYPD vehicle (5,3)
I believe the answer is:
squad car
'vehicle' is the definition.
(squad car is a kind of vehicle)
'mark circling yard' is the wordplay.
'mark' becomes 'scar' (mark left by an injury).
'circling' indicates putting letters inside (circling can mean going around or containing).
'yard' becomes 'quad' (I've seen this before).
'scar' placed around 'quad' is 'SQUAD CAR'.
'in eg nypd' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for squad car that I've seen before include "Force vehicle" , "Police patrol vehicle" , "vehicle from station" , "panda perhaps" , "Police wheels?" .)