The 44-year-old mother vanished on July 19 in 2023 and her remains were found in a shallow grave on Greenpark farmland, on the outskirts of Christchurch, just over a year later.
Chinese national Tingjun Cao, 53, is charged with her murder.
Bao was last seen heading to show a house to a prospective client in the suburb of Hornby, where the Crown alleges Cao stabbed her and left with her body in his car boot.
Attention turned to Bao's cellphone at the trial today. It was found damaged in bushes beside Christchurch's Southern Motorway near Blakes Rd the day after she vanished.
Detective Inspector Joel Syme told the court the phone appeared to have been snapped in half and police were able to track where it had been.
"Polling data indicated prior to it being found by police, Ms Bao's cellphone had been polling at Halswell Village and Tai Tapu cell towers."
Blakes Rd resident Neil Clode gave evidence, saying his attention was attracted by a car on his street on the evening of July 19.
"About 6.15pm on the Wednesday night I was going out for tea and I went out for my car and I saw a car across the other side of the road with its lights on and I saw someone walk around the front of the car.
"I then went back inside to get my wallet, and as I was standing at the dining table to grab my wallet the headlights of the car were then pointed towards my house with the high beam lights on," Clode said.
"I thought that was strange at the time because not many cars usually do that, they usually parked in the cul-de-sac pointing their headlights towards the motorway."
When Clode and his wife headed out in the car for dinner they saw the vehicle again and followed it.
"I accelerated to chase him, to catch up with him... I thought whoever was driving in the car was up to no good," he said.
He noted the details of the vehicle at a red light, including its registration number.
"It was a dirty four-door silver sedan with a dent in the left hand side of the boot and it had a sticker on it as well," Clode said.
Flatley said he was driving along Hudsons Rd about 4.30pm on July 19, when he was drawn to a silver car parked up at a strange angle after he crossed the intersection at Greenpark.
"I was suspicious because it was parked at 45 degrees to the road and the rear of the car was at the edge of the tarmac, presenting a road hazard."
Flatley said he slowed right down going past it.
"I noticed no one was in the car, and to my shock when I passed the car there was a man crouching at the rear driver's side door.
"I looked at him, he looked at me. He had a concerned look on his face. He was crouched but he had nothing in his hands.
Flatley said he saw no one else inside or outside the car.
"I would've seen somebody in the car if they were sitting up."
Flatley said he got in contact with police after hearing a media report that police were appealing for sightings of a vehicle in the Greenpark area on July 19.
Several days after Bao's disappearance, police appealed to the public for sightings of a silver Mitsubishi sedan, registration DPH101.
Det Insp Syme said this number plate was found to be registered to the accused.
"Cao's vehicle had been seen on traffic cameras in the same or similar areas at the time Bao's cellphone was polling in those areas [Halswell and Tai Tapu]. Cao was suspected in being involved in the disappearance of Bao," he said.
Cao's defence lawyer Joshua MacLeod said yesterday that the Crown's evidence was not enough to prove a murder charge, and the evidence was much muddier than the Crown wanted it to appear.
The trial began on October 21 and was expected to run for six weeks.
