Radio car in accident concealed instrument (7)
I believe the answer is:
ocarina
'instrument' is the definition.
(ocarina is a kind of instrument)
'radio car in accident concealed' is the wordplay.
'concealed' indicates the answer is hidden within the clue.
'OCARINA' can be found hidden inside 'radio car in accident'.
(Other definitions for ocarina that I've seen before include "music-maker" , "Wind instrument with a mouthpiece and finger holes" , "Bird-shaped flute" , "Terracotta wind instr." , "Simple wind instrument" .)