Outlaw in Mini? Carl Batty! (8)
I believe the answer is:
criminal
'outlaw' is the definition.
(I know that outlaw can be written as criminal)
'mini? carl batty' is the wordplay.
'batty' is an anagram indicator.
'mini'+'carl'='minicarl'
'minicarl' is an anagram of 'CRIMINAL'.
'in' acts as a link.
(Other definitions for criminal that I've seen before include "hood" , "Felon, lawbreaker" , "Person who breaks the law for a living" , "Being sought by police" , "Violating the law" .)