Police are appealing for witnesses regarding a 'driving matter' on the Mountain Road.
The incident happened last Wednesday at around 4.45pm between Kepple Gate and Windy Corner.
Officers now want to speak to anyone who was in the area and saw a 'near collision'.
It involved a bluey purple hatchback car which was taken over by a white SUV on a blind corner.
This caused the vehicle to stop suddenly to avoid a head on collision.
If you have any information, you are asked to contact Douglas Police Station on 631212.