Officers would like to identify the driver of a dark coloured vehicle that was travelling behind a blue Nissan Micra that crashed on the A337 just before 9.30pm on Friday 8 March.
Both vehicles were travelling between Lyndhurst and Cadnam at the time.
A dark coloured vehicle attempted to overtake the Micra but had to abort due to oncoming traffic and in doing so collided with the Micra.
The driver of the Micra lost control and span off the road and into a tree. The dark coloured vehicle failed to stop.
Officer investigating would like to hear from anyone who was also travelling along this stretch of road on Friday night who witnessed this incident, or who has dash cam footage.
Officers would also like to ask whether anyone has noticed a dark coloured vehicle with recent damage to the front nearside.
Please call 101 and quote 44190082618.
If you have any information, please contact us on 101, quoting reference number
In an emergency, call 999.