Schwaab was also declined an acquittal on the charge of attempted murder.
The pair were sentenced in December last year; Schwaab to six years and seven months imprisonment and MacKay to four years and five months.
On September 19, 2020, Schwaab visited Mackay at his house. When there he took out a gun to fire at a target in the backyard.
Another friend put the gun in a metal box and placed it in the footwell of MacKay's car.
The three men travelled to Schwaab's home in MacKay's car. His parking outside would be the trigger for a near-fatal argument.
When the group started to leave about two hours later, Schwaab got into an argument with an elderly neighbour over the way MacKay had parked.
Schwaab then punched the neighbour. MacKay and the third friend were waiting in the car nearby when Schwaab got in the back seat.
Wihongi, who witnessed the punch, approached the neighbour, concerned about the language that was being used when children were playing at a nearby park.
CCTV footage captured what happened next.
It showed the vehicle, driven by MacKay, veering across the centre line towards Wihongi, slowing down, and as it went past Schwaab fired four shots through the rear window.
None of these shots hit Wihongi, however the car then came back and four more shots were fired.
Wihongi was shot three times and needed surgery for his wounds. His arm was shattered and bullets had also struck his back and hip.
Defence lawyer Andrew Mckenzie, representing Schwaab, said at the appeal hearing last month his client never intended to harm his victim, only to scare him.
After the incident, all three men in the car were charged with attempted murder, wounding with intent to cause grievous bodily harm and unlawfully possessing a firearm.
The Crown withdrew the charges against the third man, however MacKay's lawyer Nicholas Chisnall argued this was unfair and resulted in a miscarriage of justice.
The court disagreed with this, and said the decision "could not have had any effect on the outcome of the trial".
Chisnall said to do justice in the case, the alleged third party should give evidence in court.
Complicated court restrictions mean the third person, who was allegedly in the car with Schwaab and Mackay, will not opt to participate in any sort of retrial, according to the Crown.
Crown prosecutor Mark Lillico said the men's lawyers were seeking a retrial, and the sought-after affidavit of the alleged third man in the car wouldn't offer anything new if the matter was to come back before a jury.
Lillico said the "remedy" they sought was hollow and unachievable and argued that the discounts applied to their sentences were on the higher end given their lack of remorse.
Although there was potential for a new trial, the Court of Appeal said there was no "utility" in directing one on the firearm charges alone.
It ruled there would be no retrial.
