Leaving outskirts, caused carnage driving this? (4,3)
I believe the answer is:
used car
'this?' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'leaving outskirts caused carnage driving' is the wordplay.
'leaving outskirts' indicates the answer is hidden within the clue (letters on the outskirts must be removed).
'USED CAR' is hidden in the letters of 'caused carnage driving'.
(Other definitions for used car that I've seen before include "Second-hand motor" , "Previously-owned motor" , "Second-hand vehicle" .)