This comes after Gary Cowley, 59, of Manurewa died in hospital on Thursday, almost three weeks after the driver allegedly hit multiple pedestrians.
Six people were treated at Middlemore Hospital with a range of injuries following the crash on Sunday, March 20 around 1pm.
"Police's thoughts and sympathies are with his family at this difficult time," said Detective Senior Sergeant Kevin Tiernan.
Another person who is believed to be Cowley's wife, and was also seriously injured, remains in a stable condition in hospital.
All other victims have since been discharged.
A woman who witnessed the aftermath of the incident said she joined other shoppers in rushing to the aid of the injured after hearing a "big bang" at 1pm.
She said the sound of the impact was so loud she initially thought a truck must have slammed into the low ceiling of the car park.
The woman is due to appear at Manukau District Court on May 10 to enter her plea on all 16 charges.