A spokeswoman said a description of the car as a black Holden station wagon with no plates that was shared on social media matches a possible description given to police at the scene.
A St John Ambulance spokeswoman said one person in a serious condition and one in a moderate condition were taken to Hawke's Bay Hospital.
A Hawke's Bay District Health Board spokeswoman said a man and a woman both in their 20s are in a serious but stable condition.