The camera operator inside was unharmed, but his car was damaged and had to be towed from the scene.
Police say the offending vehicle was a previous black or dark gray Nissan Navara, and have urged panel hitters to be on the lookout for matching cars in need of frontal repairs.
Investigators want to talk to anyone who has seen a vehicle that matches the description in the area around the time of the incident.
The incident is the second of its kind involving a mobile speed camera in Victoria recently.