A Game Ready Driver has just launched for DiRT Rally VR. GeForce Drivers 368.69 WHQL increments upon the last release, obviously adding optimizations for DiRT Rally VR, but it also includes a few new SLI profiles (Armored Warfare, Dangerous Golf, iRacing: Motorsport Simulator, Lost Ark, and Tiger Knight) and probably other bug fixes.
The update doesn't yet have a release date, but it should be soon. According to NVIDIA's blog post, it sounds like it will come first to the Oculus Store, but arrive on Steam later this month. I haven't been following the game too heavily, but there doesn't seem to be any announcement about official HTC Vive support that I can find.
You can pick them up at NVIDIA's website or through GeForce Experience. Thankfully, the GeForce Experience 3 Beta seems to pick up on new drivers much quicker than the previous version.