Here’s what I’m thinking: Forza Horizon 2’s pre-order bonuses should be announced sometime soon, and I’m guessing that the Huracan will be a pre-order bonus DLC code for FM5.
That seems to be the most likely thing to happen at this point. Though I still don’t know if they’d wanna give away their cover car to a game already out whatsoever. It’d be like FM4 getting the P1 as a DLC before FM5 even launched…