A Crown summary says two people had been sitting in a silver-coloured VW Golf parked in Tomoana Rd, near Cornwall Park, about 6.20pm.
Gillies-Ngaronoa and another man parked nearby in a vehicle which soon afterwards moved to block the VW's exit.
Gillies-Ngaronoa knocked on the window of the VW and asked for a cigarette lighter, walked away momentarily and returned to demand that the door be opened.
Once the door opened, Gillies-Ngaronoa ordered a male to get out and empty his pockets, and showed the man and an accompanying woman that he had a pistol in his jacket. The woman also got out and emptied her pockets.
Gillies-Ngaronoa got into the VW and drove off, the car still containing the victims' cellphones.
About two hours later police saw the stolen vehicle driven by Gillies-Ngaronoa in Camberley, but it did not stop and hit speeds of 110km/h in a 50km/h area, sometimes crossing the centreline in the face of oncoming traffic.
Bottles and other objects were hurled from the car towards pursuing patrol cars. The VW collided with a patrol car at the intersection of Takapu and Orchard Roads but continued on Orchard Rd before colliding with another patrol car.
While Gillies-Ngaronoa was being extricated to be taken to hospital, the co-offender fled and was apprehended soon afterwards, with a wound to one leg apparently caused by the discharge of the robbers' firearm during their flight from police.
Defence counsel Roger Phillip contended there was minimal premeditation but Judge Mackintosh said approaching the couple in the carpark, and the use of a firearm, with indications it may have been loaded, pointed to some degree of planning.