I think that upgrade to rally2 car is intended for those older models - i20, Fiesta (because I don't think they will build new models). Citroen will probably not be updated anymore (it will "upgrade" through Lancia), VW Polo doesn't have support, so no go for that car. Skoda and Toyota are currently the best cars out there and are updated reguraly, so they don't need any major improvements. i20 and Fiesta on the other side are amongst "slower" cars, so they are refferong to those two. It's only due to this that M-Sport and Hyundai could compete against Lancia, Toyota and Skoda and not be automaticaly way behind.