Police are on the hunt for information to identify the people responsible for throwing a rock onto a car from the M1 overpass at Dapto overnight.
An 18-year-old man called Triple Zero after his windscreen was shattered as he drove along the freeway.
The man told police he was driving his Hyundai with two passengers under the Fowlers Road overpass about 8:40 pm on Thursday 18 April when a rock smashed into the windscreen.
The man called Triple Zero (000) and alerted police to the incident.
Police from Lake Illawarra Police District went to the scene but could not find anyone in the area.
Inquiries are continuing into the incident, and police ask that anyone with information or dashcam footage call Crime Stoppers on 1800 333 000.
Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au. Information is treated in strict confidence.