Instrument installed in radio car in advance (7)
I believe the answer is:
ocarina
'instrument' is the definition.
(I know that ocarina is a type of wind)
'installed in radio car in advance' is the wordplay.
'installed in' indicates the answer is hidden within the clue.
'OCARINA' is hidden within 'radio car in advance'.
(Other definitions for ocarina that I've seen before include "Toy-like wind instrument" , "toy instrument" , "we blow it" , "Flute-toned musical toy" , "Toy flute" .)