An 18-year-old man has been arrested in relation to the serious assault of an elderly Onehunga couple on Saturday night.
The Otahuhu teenager will appear in Manukau District Court on Tuesday charged with unlawfully taking a vehicle.
Police said officers were still investigating the incident and were yet to locate the person responsible for the attack on the couple.
The couple were attacked in the driveway of their home on Mt Smart Road.
Their Toyota Vitz was stolen and later used to ram another vehicle with a family inside.
The wife pulled into the driveway and was approached and verbally abused by a man.
The noise attracted her husband's attention, and when he came outside the attacker beat him unconscious.
He then attacked his wife and she too was knocked unconscious, police said.
The couple were taken to hospital and left with severely bruised faces and significant jaw injuries.
They are currently recovering at home.