Police say they want to trace the driver of a white van on the mountain road on Thursday afternoon (7 August) after part of its load flew out of the vehicle and hit an oncoming car.
The incident happened near the Mountain Box at around 1.45 pm.
An object flew from the van, described as similar to a Ford Cargo, as it headed towards the Black Hut, and hit a blue Citroen Berlingo travelling in the opposite direction, towards Ramsey.
Offices want to speak to the owner of the van, anyone who noticed it on the road or who can provide any further information.
If you can help, contact Ramsey police station on 812234.
Warning over flare disposal after amenity site fire
Drug-driver jailed after passenger injured in crash
Suspended sentence for 56-year-old in cannabis supply case
Owner of a block of flats fined for failing to meet fire safety regulations
Review of taxi fares extended to assess impact of Middle East conflict