Vehicle carrying Latin duo (6)
I believe the answer is:
couple
'duo' is the definition.
('couple' can be a synonym of 'duo')
'vehicle carrying latin' is the wordplay.
I cannot really see how this works, but
'latin' could be 'l' and 'l' is present in the answer.
'vehicle' could be 'coupe' (coupe is a kind of vehicle) and 'coupe' is found within the leftover letters.
No letters remain.
This explanation may well be incorrect...
(Other definitions for couple that I've seen before include "Unite" , "Two of a kind" , "Pair - put together" , "Pair, duo" , "Pair of attached people" .)