Drive away racecourse spy in exchange of fire (5-3)
I believe the answer is:
shoot-out
'exchange of fire' is the definition.
'drive away racecourse spy' is the wordplay.
'drive away' becomes 'shoo' (shooing is a kind of driving away).
'racecourse spy' becomes 'tout' (gambler who scouts out a race course).
'shoo'+'tout'='SHOOT-OUT'
'in' is the link.
(Other definitions for shoot-out that I've seen before include "Penalty showdown?" , "Gun battle" .)