Turn over a vehicle in the morning — it rattles! (6)

Here is my best explanation:

'it rattles' is the definition.
(rattling instrument)

'turn over a vehicle in the morning' is the wordplay.
'turn over' is a reversal indicator.
'vehicle' becomes 'car' (car is a kind of vehicle).
'in the morning' becomes 'am'.
'a'+'car'+'am'='acaram'
'acaram' back-to-front is 'MARACA'.