We were travelling , towing our van, south of Perth on the Forrest Hwy and couldn't believe that an over width vehicle could pass another over width vehicle. We couldn't even pass with our van, but they did. If one had clipped the other I hate to think of the carnage that could have followed. I rang the local police to report the incident and the female officer told me they do it all the time, highly illegal, but think as they have a pilot vehicle it's ok! Not!