Actually I would love to see a 6R4/Audi S1 Rally supercar series, but these would be wasted without the full dirt/snow tracks.
Failing that, though, I would love to see a rival car for the UF1 (fiat styles have been mentioned) and a rival for the Scirocco maybe, but maybe not on this.
Purely because I'm me, I'd love to see a small lightweight roadster (rwd) with all the weight at the front... thinking Triumph Spitfire or MG B Roadster maybe even a Stag.
I would also like another 4WD, possibly something slower, put it in the range of the STD class...