You and everyone else who considered buying this game for Xbox 360 based on information available prior to release was mislead. Turn 10 has no plans to support you after your purchase with DLC or updates for more than obvious bugs.
For more information please refer to this thread http://forums.forza.net/turn10_postsm207903_Forza-Horizon-2-on-Xbox-360.aspx#post_207903
No one was mislead, because it even said Xbox One in most everything regarding Horizon 2’s release information.
They only mentioned Xbox 360 a few times. Anyone assuming otherwise, did it to themselves. As has been discussed many times over on these forums since release.
Assumptions aside, they should have been up front from the start. If they were, there wouldn’t be some many complaints.