"It's unbelievable. It really is a miracle survival. They pulled everyone out of the gully and I don't know how the hell they lived," she said.
"You can't see the car from the road because it's gone into the gully and is hidden by trees."
The worst injured person, a young man, suffered a broken shoulder in the crash.
Fire and Emergency said four people were initially trapped in the vehicle.
Police organised a rescue team to go to the scene. The rescue helicopter was turned around mid-flight.
Police said all those inside the car were out and being treated by medical personnel.
St John Ambulance said four people, three with moderate injuries and one without injury, were taken to Waikato Hospital.