Control old car seized by gangster (8)
I believe the answer is:
dominion
'control' is the definition.
(I know that dominion is a type of control)
'old car seized by gangster' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'car' becomes 'mini' (Mini Cooper).
'seized by' is an insertion indicator.
'gangster' becomes 'don' (mafia don).
'o'+'mini'='omini'
'omini' inserted into 'don' is 'DOMINION'.
(Other definitions for dominion that I've seen before include "Area of control" , "Territorial possession controlled by a ruling state" , "Quieter repeat" , "eg Canada" , "Authority to rule over and control people" .)