In court this morning Ing said that after he drove Liev, known as "Jack", and Soa to a town later established to be Parakai, he was told to take them to an address in Mangere.
It's alleged Prutsiriporn was held there in the garage after being kidnapped from her home 24 hours earlier.
Ing said not long after they arrived, Liev said he and Soa wanted to go for a drive - he assumed it was something to do with drugs.
When they got back, a Thai man asked Soa whether there were any police around and he replied that there weren't.
A Maori man - who the Crown alleges to be Luigi Havea - then came through the back door.
"That's the first ugly man I ever saw in my life."
Ing said Liev asked him if he knew why they were in Mangere.
"Jack said, We're going to take your car and put a Thai lady in your boot," Ing told the court.
The witness said he told them: "What the hell?"
"I was like you can't do that to me. I've got a family, I've got kids. You can't do that."
The Crown says while in the boot of Ing's car, Prutsiriporn found a knife and wrapped it in foam then hid it down her trousers.
She also found a chef's steel and used it to gouge open the boot while they were stopped at traffic lights in Huia Rd, Papatoetoe.
Prutsiriporn was found nearly unconscious, barely breathing and foaming at the mouth with ties around her neck, waist and ankles.
She died in hospital two days later.
A pathologist concluded she suffered at least three major blows to the head, only one of which could be caused by Prutsiriporn coming out of the boot, prosecutor Gareth Kayes told the jury last week.
WHO IS ON TRIAL: Seng Lek Liev, Aphichart Korhomklan and Luigi Havea: defending charges of manslaughter and kidnapping.
Masi Vaifali and Joseph Benjamin Haurua: Defending one manslaughter charge each.
Tevita Matangi Fangupo: Defending a charge of kidnapping.
WHO HAS PLEADED: Soaradith Soa: Admitted manslaughter and kidnapping and is not part of the current trial.
Raymond Brown and Panepasa Havea: Have both pleaded guilty to kidnapping. Both aren't part of the trial.
THE DEFENCE: Defence lawyer Mark Ryan said Luigi Havea's brother, Panepasa Havea, organised the kidnapping because the victim owed him money for drugs.
Sen Lek Liev did not knowingly do anything to aid or assist in the kidnapping.
Aphichart Korhomklang just wanted to buy drugs and had no idea about the "conspiracy" to kidnap the victim, said his lawyer Hugh Leabourn.
Luigi Havea wasn't a member of the Head Hunters or the "ghost unit" so couldn't have been part of the kidnapping and manslaughter, lawyer Michael Kan said.
Masi Vaifale has pleaded guilty to kidnapping and his lawyer John Munro said once his client's job was done, his role was over so couldn't be convicted of manslaughter.
Tevita Matangi Fangupo's denies "any" kidnapping.
Joseph Benjamin Haurua's lawyer, Murray Gibson, did not do an opening statement.
The trial, in front of Justice Matthew Palmer, is set down for 12 weeks. More than 100 witnesses are expected to be called.