Jayde Amber Moscay, 20, and Anthony James Glover, 23, are standing trial in the Downing Centre District Court over the alleged incident, which dates back to 2012.

Both are facing a string of charges, including causing grievous bodily harm and using an offensive weapon to avoid apprehension by police.

The trial, which opened on Tuesday and is expected to last several weeks, heard that bags of dirt and rocks were seen being hurled out of the white Holden Commodore as it travelled along the New England Highway before turning onto the Guyra-Ebor Rd on November 1.

The court was this week told five people allegedly led police on a high-speed car chase for more than 80 kilometres, but two of the occupants – Moscay and Glover – say they had nothing to do with the rock-throwing and had simply thought they were going “on a ride through NSW”.

The prosecution alleges the rock-throwing forced motorists off the road before one man was critically injured when a rock shattered his window and hit him on the forehead.