The car that was allegedly involved in a crash that killed four people was travelling in excess of 150 km/h, according to the Crown.
Dylan Cossey and Stephen Jones, who are both 20, are on trial in the High Court in Hamilton facing four charges each of manslaughter.
They also face one charge of racing, and failing to stop to ascertain injury.
Mr Jones also faces a charge of attempting to pervert the course of justice after editing a video he took in the car at the time.
The crash happened on State Highway Three near Hamilton Airport late in the evening of 24 June 2016 .
The Crown said the two accused were racing a Nissan Skyline when it lost control and hit a van coming the other way.
The driver of the Nissan - who was 28 - died along with three of his passengers aged 19, 20 and 24.
The van's driver was seriously injured.
The Crown told the jury that the accused drove through the crash site and did not stop to see if anyone was injured. They drove on to Hamilton.
Even though the accused's car wasn't directly involved in the crash, both men share liability, the Crown said.
Mr Cossey's lawyer told the court that the driver of the other vehicle caused the crash and that Mr Cossey was not responsible for the other person's driving.
Mr Jones' lawyer said his client was merely a passenger.
The trial before a jury of seven women and five men is set down for about two weeks.
Justice Hinton is presiding.