I'd also think that the M5 will be available on the Nürburgring GP track for time trial.
The 599 GTO, Impreza STI and the Mercury Cougar will probably available on the Bernese Alps tracks to race with.
That'd be the build they've used during Gamescom and E³, most likely, and I don't think there'd be much of a reason to deviate from that.