Shaun Thomas, 33, had the weapons in his glove box and a tool box and told police he needed them for protection on long trips, court documents show.

He failed to appear before Dubbo Local Court to face two charges of possessing a prohibited weapon and a charge of having custody of a knife in a public place.

He was convicted in his absence and a warrant for his arrest was issued to bring him to the court to be sentenced.

Police sighted a green Ford Falcon bearing Victorian registration plates on the Newell Highway near Dubbo about midday on August 27, court documents show.

The vehicle was stopped for a random breath test.

Officers noticed Thomas's hand was shaking as he handed his licence out to them and he was avoiding eye contact with them, court documents show.

In a conversation with police, the driver said he had travelled from Melbourne the day before and was on his way to the Gold Coast where he was moving to, but he said he was not sure of his new address, court documents show.

Police noticed Thomas appeared nervous, with him shifting his weight from one foot to another and speaking quickly.

Thomas was told police had trouble with people transporting large amounts of illicit contraband interstate through western NSW and he gave permission for a search, saying nothing was in his car.

Police found a large knife that could be folded and a pair of steel knuckle dusters in the glove box and a second set of knuckle dusters in a tool box, which he said he had made.