That, Custaxie50, is like asking for the meaning of life.
It is my personal opinion that most of us involved in the construction or modification of saloon cars prefer to work to a simple set of rules that make whatever they allow easily achievable while allowing us to have a greater input of ideas as to how this is achieved. By that I mean that a situation like the NZV8 supertourers where the chassis are all identical is not my idea of an ideal class. Please don't get me wrong, with a full field of entries these can be quite spectacular, but we need just that, a full field to create the spectacle that will get the punters bums on seats. But those cars are all the same except for a few bolt on panels and the badges. It doesn't matter how excited the commentators get about the "Ford verses Holden" stuff but in reality they are all an identical space frame and Chevy motor. To me the NZV8s are better because at least they start will a real car and turn it into a race car allowing those who build and maintain them to have some input into how they achieve the end result. I actually feel the same about the Aussie V8 supercars but they attract large crowds because of brand loyalty and the spectacle that the sometimes put on. I find the DTM to be so far away from reality as to be not worth watching.
I have thought for some time that world motorsport needs a class where it is possible to build a car anywhere in the world and be competitive. But it would have to be a class based on real cars not some quasi silhouette hot rod. For example how about a world wide class based on basic 4 door saloons running 6 cylinder engines up to 4 litres with no aero other than that fitted to the original base model, no great big flared gaurds, with no paddle or sequential gearboxes and major restrictions on wheels brakes and tyres. And on the point of tyres leave that open for competitors to use whatever they want within restrictions placed on them over sizes and quantity per meeting. Why? Because it gets a greater number of tyre companies involved which must benefit the series. And then hold a world series in as many different countries as possible, just like the old group A. We have in both NZ and Aus the skills and people to build a winner give a "sensible" set of rules. I think what tends to happen is the rules get too complicated and too expensive to allow for the backyard guys who would get involved in such projects.
It is also my belief that apart from the once a year visit of the Aussie V8s most motorsport is run for competitors and not spectators. If you went to the Ganley festival and looked at the crowd most there had been involved in some way in motorsport during their lives.
Allan