A man allegedly involved in throwing rocks out of a car during a high-speed pursuit with police just wanted to go for a drive, a court has heard.

A passing driver suffered a serious head injury from a rock thrown from another car speeding up to 150km/h during a police chase, a court has heard.

After that, the car continued, hitting a truck with another rock before doing a u-turn and driving towards a pursuing police vehicle head on.

Anthony James Glover, 23, and Jayde Amber Moscay, 20, were in the car with three others when they became involved in a number of high-speed pursuits as they sped from Queensland into NSW on the morning of November 1, 2012.

The pair, who have pleaded not guilty, are facing a number of charges, including throwing rocks out the car in a bid to hinder police arrest and of causing grievous bodily harm to Pat Garrett, whose car was hit by the rock.

At the opening of their trial on Tuesday, Sydney’s District Court heard how bags of dirt, rocks and possibly even a beer bottle were seen being hurled out of the Commodore as the five travelled into NSW, often forcing other motorists off the road.

After being pursued by a police officer just outside Glen Innes, where the car was seen going more than 150km/h, crown prosecutor Michael McColm said a rock hit the car Mr Garrett was in, causing him grievous bodily harm.

“It bounced off the bonnet, through the windscreen, struck Pat Garrett in the forehead and caused him an immediate serious head injury,” he told the jury.

When police eventually reached them, they were all arrested.

While Mr McColm said the crown cannot prove who threw the rocks, it alleges Glover and Moscay were part of a joint criminal enterprise.

But Glover’s barrister Susan Kluss said her client had candidly told police – after the five were eventually apprehended – that he didn’t want to be part of the pursuit.

“He thought he was going for a drive into NSW,” she told the jury.

The trial continues.