i think the problem is just how we call such new cars...
i'm totally against the rally2 solution. we already have a similar thing that's erc and it's not the dreamland people see for the top tier. there's the need of a top tier, clearly.
so keep the rally1 name and make a reg that's a step (backe if you want, but who cares?) toward wrc spec style, that's proven a good balance. it can be cost capped at half a current rally 1 , and that's still nearly 2x a rally2, which mean space for sensing the difference between the 2, but way more affordardable if costs is the problem (which i don't buy, btw).
still, thing is: how a top tier car should be? engine-wise (power source) and maybe suspension/tyre also, more than aero/restrictor.