A police investigation has been launched into a social media video that appears to show a driver hitting more than 150mph.
The incident had taken place on the A75 between Eastriggs and Annan on 23 October, at around 3:50pm.
Police Scotland have said it involved a dark-coloured performance model Volkswagen.
Officers are now appealing for anyone with information or dashcam footage to come forward.
They are also keen to trace drivers who may have been on the A75, the adjoining C43(a) Eastriggs Station Road, or the B6357 Stapleton Road, Annan - before, during or after the incident.
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