Check out the kilowatt differences in these banned and allowed vehicles -
Apparently, P-plate drivers can drive a Porsche 968, the non-turbo Lotus Elise and Lotus Exige (like AusBluesMan said) and the Honda S2000.
It's been said before, but I'll say it again - the Victorian system may fix a few of these problems
The only solution to all this is EXTREMELY impractical - assess each and every individual car model. No way they can do that, so we will just have to put up with these discrepancies no matter what system is implemented.
It works pretty well with motorcycles, x bikes are allowed, rego sticker is stamped with LAMS.
To get the rego, need to get your car dynoed if it were a certain type/modified + you wanted the restriction exemption.
Pros: efficient, still just as easy to catch people out. Can have the car you want if it meets a specific tuning requirement, and you personally have to go to the effort to ensure its legal, so it doesn't fall in the hands of the RTA or whatever to personally test every car, just walk into the RTA come rego time with engineering certificate and bobs your mums bro.
Cons: ???
It most certainly isn't any less efficient than the current system we have, nor would it be harder to police. Quick look at the rego sticker would rule out any problems. Somewhere along the line they just got lazy and applied a bandaid fix to a problem that didn't quite exist. Then they realised how backwards it was and started handing out exemptions like hotcakes (most european brands would get you off the hook if it's the only car you have access to even though RTA literature says they won't grant exemptions on that basis).
Also their reasoning with the 180kw commies/falcons was that they were popular family cars, and too many people would be without a car by banning them.