In old vehicle at first, a ceramic wind instrument (7)
I believe the answer is:
ocarina
'ceramic wind instrument' is the definition.
'in old vehicle at first a' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'vehicle' becomes 'car' (car is a kind of vehicle).
'at first' means one lot of letters go next to another.
'o'+'car'='ocar'
'in' after 'ocar' is 'ocarin'.
'ocarin'+'a'='OCARINA'
(Other definitions for ocarina that I've seen before include "music-maker" , "Toy flute" , "Bird-shaped flute" , "Toy-like wind instrument" , "Old wind instrument" .)