I think it is almost impossible to have regular manufacturers in ERC. If company is giving money to sport programme, they always wants to be in WRC... Earlier or later. To have Skoda and Peugeot it was possible only because their "group" partners VW and Citroen were in WRC. If we dont talk about "private" manufacturers like Proton and Opel in S2000 era, only one brand without WRC was Fiat (and they were thinking about WRC)...

We will see how it will be with other R5 manufacturers, if they will be interested also in ERC...