Update: AMD has also released its own Forza Horizon 3 optimized driver update for PCs with its Radeon graphics cards. The Crimson drivers have the version number of 16.9.2.
The full release notes for the new 372.90 drivers also include a number of bug fixes, along with some unnamed security updates. We expect AMD to release its own Crimson drivers for its graphics cards that will also be optimized for Forza Horizon 3 in the near future. The game will be available to play for buyers of the Ultimate Editon on September 23, and for everyone else on September 27.