A spokeswoman for Auckland Hospital said two 17-year-old girls remained in hospital in a stable but improving condition.
The 16-year-old driver of the car was discharged from hospital last week, and a 17-year-old passenger was discharged over the weekend.
Detective Inspector Scott Beard said police were still arranging times to speak to the occupants of the stolen vehicle.
"We want to do the full investigation before we start determining if, what and when we would charge."
He would not go into detail about what police had established so far, nor discuss what charges the girls might face, until the investigation was complete.
"We need to make sure we've spoken to everybody and then determine where we're heading."
Police were working with the Independent Police Conduct Authority, which is investigating the pursuit.