Understood to have not received broken bones, the boy is a Year 9 pupil at Napier Boys' High School.
The car was driven by a Napier woman taking her child to ballet. Mr Chard said: "She wouldn't have been able to stop."
An ambulance and police officers were soon on the scene.
The boy lay conscious on the road as the crew from St John Ambulance arrived to tend him.
Police closed the section of Tennyson St from Dalton St to Clive Square and diverted traffic.
The scooter was seized as part of the investigation.
He was last night reported to be in a critical condition in Hawke's Bay Hospital.
While the incident did not happen on the way to or from school, Napier Boys' High School principal Ross Brown yesterday told an assembly that scooter riders should wear helmets and that riders needed to take more care about where and how they were using their scooters.
"We have a lot of boys scootering to and from school and, yes, we are contemplating telling them that, if they are, and they are in school uniform, then they must wear a helmet," he told Hawke's Bay Today last night.
"This is certainly a strong warning that kids are taking things too far," he said. "Bike and bicycle riders are respected users of the road and they have to use helmets, but where does the law stand with scooters? Maybe there does have to be a string of laws."
Police Senior Sergeant Greg Brown, who did not attend the crash scene, said he was not aware of specific complaints about scooter and board rider behaviour in the vicinity of the carpark.
"But we do get complaints," he said, echoing the messages delivered by the school principal.
The husband of the car driver had last night been updated on the condition of the boy.
He said: "We hope he recovers."
His wife and daughter were "very shaken up" by what had happened, he said.