They used to have a list of cars that are banned full stop, the power to weight ratio thing didnt even come into it, you were just not allowed to drive them, I dont know if this list still exists but presume so, as said before if your car is on this list, dont try the power to weight thing with Mr plod as you will lose, I might drop into the Vic roads and get the list next week and see whats on it. I would advise anyone else on P plates to do the same, as it would be a shame to have your new ride sitting in the shed as you cant drive it.
here is an outake from Vic roads
High powered cars
While you can drive most vehicles, you are not permitted to drive a high powered car. These are cars which have a power to weight ratio greater than 125 kilowatts per tonne or with a capacity to weight ratio of more than 3.5 litres per tonne. A list of cars which may not be driven is available from VicRoads Registration and Licensing offices.
You may drive a high powered car if your employer requires you to drive it in the course of your
employment, or if you hold an exemption issued by VicRoads. VicRoads will only grant an exemption if:
• it is the only car owned by your family
• the car is used for business as well as social use and no other non high powered car is owned by your family.
Applications for a high powered vehicle exemption must be made in person at a VicRoads office. Exemptions are for a nominated vehicle and must be carried at all times