Toyota NZ had been busily testing the car on an engine dyno during the week to try and find out why the car's throttle cut-out system kept continually switching on at Cromwell.
"Other than that, a better round from the last and looking to improve more in the next races," said Ngatoa.
Weather conditions got rough enough by Sunday morning that Toyota Racing NZ decided to cancel the remaining races for the Castrol Toyota Racing Series cars, which are open wheel, due to the high winds potentially compromising the downforce of the high speed formula TRS vehicles.
But the Toyota 86's carried on and ultimately Auckland's Jordan Baldwin - Rookie of the Year last season – laid down a strong challenge for the title as he picked up two wins to claim the round and move from third to leading the championship table.
In Saturday's first race there was an early red-flag and Baldwin had to fight his way past pole-sitter Jaden Ransley of Christchurch.
Then series leader Callum Hedge (Auckland) fell back from fifth to tenth behind Ngatoa, while Cambridge's Connor Davison and Hamilton's Mitch Hughes crashed out, bringing out the red flag.
With Baldwin gone for the win, the closest fight on the track was for seventh as Auckland's Connor Adam had to hold off challenges from Ngatoa, Hedge and Stratford's Campbell Stewart, who ultimately finished eighth.
On Sunday, Ransley had a costly penalty in the second race, which was also won by Baldwin, while Hedge came fourth.
Ransley then won the third race with Baldwin second and Hedge fourth again, meaning both Baldwin and Ransley jumped ahead of him, dropping back to third in overall points.
The penultimate fifth round will be held during the NZ Grand Prix meeting at Manfeild on the February 8-9 weekend.
2018-2019 Toyota 86 Championship
Top 10 points after Round 4: 1. Jordan Baldwin 735; 2. Jaden Ransley 722; 3. Callum Hedge 712; 4. Peter Vodanovich 603; 5. Connor Adam 578; 6. Brock Gilchrist 543; 7. Arran Crighton 484; 8. Jacob Cranston 445; 9. Kaleb Ngatoa 430; 10. Campbell Stewart 391.
