there has been a small patch to fix the audio
Version 1.22 Fix list - Steam
· Audio - Engine and Co-Driver balance is now back to how it was in 1.20.
· Audio - Surround now works like it did in 1.20.
· Audio - Engine audio during post race sequence now plays out correctly.
Still doesnt go through Rift by default. I have to set rift to my primary audio device which i never had to do before.
Not exactly hard to set in the options but to me it work working fine before the patch and now its not. I never noticed anything fixed in the patch notes either - the biggie for me was that fps would drop to ~70 for no reason on some tracks even when CPU and GPU were setting at 60% usage