I know a guy, who knows a guy from the pub, that can hit your car with Stalker DSR and laser to test your speedo accuracy in Melbourne.

If you need to seek the services of this guy he charges $50 per 15 minutes of testing in simulated scenarios of passing highway patrol in both moving mode and static scenarios with radar and laser, constant on/instant on etc. Confirm your speedo's accuracy without the risk of getting an infringement notice. PM me if in Melbourne and you need to know your speedo accuracy in a testing environment.....