Police said the Eagle helicopter began monitoring the car after police received information about "a vehicle of interest" on the motorway near Mt Wellington about 9am today.
The blue car, which was stolen, left the motorway and was observed driving erratically through parts of the Flat Bush area, on multiple occasions putting members of the public at risk, police said.
Police staff on the ground in the area were monitoring updates of the vehicle's location, but at no point was a pursuit initiated, a spokesman said.
Officers deployed spikes near Highbrook, leaving the car's tyres destroyed.
Inspector Cornell Klussein said the Police Eagle helicopter had been following a car just before the crash.
"The person in the car was wanted for an unrelated serious crime. He started driving at high speed through roads like Te Irirangi Drive and around the Flat Bush area," he said.
"During this time, Eagle was following. We didn't have any police cars pursuing him directly. After a while, he entered the motorway going the wrong way at Highbrook.
"He crashed into a member of the public's car about 100m on to the motorway."
A witness said he was turning on to Ra Ora Drive when the blue car "recklessly" turned from that road on to Highbrook Drive, pulling in front of other cars.
"As we got closer to each other I noticed his rear driver side tyre was shredded and he was practically driving on the rim."
Just after 10am, the vehicle was driven on to the Southern Motorway using the Highbrook off-ramp and toward oncoming south-bound traffic.
Four people received injuries in the resulting collision – two people were reported to have moderate injuries, while another two sustained minor injuries.
The driver of the stolen car was in hospital, police said.
Inquiries were under way and charges are likely to be laid.
Authorities were forced to close off the motorway from Princes St for just over two hours as emergency crews attended the scene.
An AA spokeswoman said traffic built rapidly after the crash, with the trip from the city to Manukau taking almost two hours at 11am compared to the 15 minutes it would usually take at that time.
Traffic was back to normal once all four lanes were reopened just before 12.30pm.
The impact wasn't restricted to southbound journeys - people travelling northbound on the Southern Motorway also experienced delays. The trip from Manukau to the city took about twice as long as usual by mid-morning - about 30 minutes, compared with the normal 15.
