Trading centre’s vehicle facing wrong way (4)
I believe the answer is:
mart
'trading centre's' is the definition.
(I've seen this before)
'vehicle facing wrong way' is the wordplay.
'vehicle' becomes 'tram' (tram is a kind of vehicle).
'facing wrong way' says the letters should be written in reverse.
'tram' written backwards gives 'MART'.
(Other definitions for mart that I've seen before include "Take tram to market" , "US shop; market" , "Trading centre" , "Place" .)