After leaving a party on Williams St in Kaitaia, Fungavaka and Ms Manuel ended up on Pukepoto Rd, near a dairy.
He told police he had wanted to go back to the party to pick up his son but she did not want him to go there.
When he moved the car, Fungavaka said he thought her leg hit the Holden Commodore when she tried to stop him.
Fungavaka said he then did a U-turn and travelled at about 40km/h back down Pukepoto Rd on his way to the party, when he thought he had struck something.
He said he looked back and thought "Is that her or something?" but did not stop, as Ms Manuel's father George was walking across the road and was on his way home.
When asked what part of Ms Manuel's body he thought went under his car, Fungavaka said he did not know.
Being a diabetic, he said his vision may have been poor given that the car lights at the time were not switched on. Mr Dalziel asked why he did not stop at a house, dial 111, or tell anyone when he went back to pick up his son from the party. Fungavaka said he knew something was wrong but was scared to do anything.
"I was scared because of her father. If I stop, he'd kill me," he said.
Asked how much he had had to drink before Ms Manuel was run over, Fungavaka said "heaps" of vodka, Ice beer and Steinlager. After picking up his son, Fungavaka said, he drove to a female friend's house nearby and told her he thought he had run Ms Manuel over. The trial before Justice John Faire continues.