Vehicles the reverse of stylish (5)
I believe the answer is:
trams
'vehicles' is the definition.
(tram is a kind of vehicle)
'the reverse of stylish' is the wordplay.
'the reverse of' says the letters should be written in reverse.
'stylish' becomes 'smart' ('smart' can be similar in meaning to 'stylish').
'smart' written backwards gives 'TRAMS'.
(Other definitions for trams that I've seen before include "Not seen in London" , "People movers" , "public transport" , "old vehicles" , "silk yarns" .)