Talk going round Brazilian city in vehicle (7)
I believe the answer is:
chariot
'vehicle' is the definition.
(chariot is a kind of vehicle)
'talk going round brazilian city' is the wordplay.
'talk' becomes 'chat' (I've seen this before).
'going round' is an insertion indicator.
'brazilian city' becomes 'rio' (I've seen this before).
'chat' enclosing 'rio' is 'CHARIOT'.
'in' acts as a link.
(Other definitions for chariot that I've seen before include "Roman two-wheeled vehicle" , "Old vehicle (of fire?)" , "Ancient horse-drawn war vehicle" , "ride in carriage" , "American religious folksong 'Swing low, sweet ...'" .)