Drive around? No time or opportunity (4)
I believe the answer is:
room
'opportunity' is the definition.
(room is a kind of opportunity)
'drive around? no time' is the wordplay.
'drive' becomes 'approach' (both can mean a road or street).
'around?' says to take the centre (I've seen 'around' mean this).
'no' becomes 'o' (resembles 0 - 'no' can mean 'zero').
'time' becomes 'm' (I can't justify this - if you can you should give a lot more credence to this answer).
The middle letters of 'approach' are 'ro'.
'ro'+'o'+'m'='ROOM'
'or' is the link.
(Other definitions for room that I've seen before include "Space (for elbows?)" , "Space within a building" , "Opportunity, scope" , "kitchen?" , "Scope; living space" .)