Part of record player in truck (6)
I believe the answer is:
pickup
I believe this clue is a double definition.
'part of record player' is the first definition.
('pickup' is part of 'record player')
'truck' is the second definition.
(I know that pickup is a type of truck)
'in' acts as a link.
(Other definitions for pickup that I've seen before include "Small van" , "Hear" , "Actor Ronald" , "rally > vehicle" .)