Police in Suffolk are searching for the driver of a sports car they said rammed a vehicle and fled, leaving another motorist with serious injuries.
A dark blue Porsche Boxster was in collision with a Vauxhall Nova, after which the Porsche's driver fled on foot, police said.
The collision took place on Saturday at about 2220 BST on the A134 Long Melford bypass near Sudbury.
The 19-year-old driver of the Vauxhall received serious chest and leg injuries and was taken to the West Suffolk Hospital at Bury St Edmunds.
His injuries are not said to be life-threatening.
His teenage passenger received minor injuries in the crash.
Suffolk Police have appealed for anyone who witnessed the collision, saw the Porsche earlier in the day, or who can identify the driver to come forward.