Wow, just got in with my 99 this morning and it's been quite a day. Got to use it once and then each subsequent drive showed autosteer and cruise as unavailable. Attempted to use the trick of unplugged my SSD and turning off sentry, but this only worked once. Then like many of you, started getting the erroneous FCWs galore. Had to visit a family member and couldn't use FSD beta or even basic AP after I turned off FSD. I had to turn off the FCW, set to none, as it was just endlessly alerting. TACC would engage and disengage after about 10 seconds on the highway. However, I was on the highway traveling around 65 or 70mph on my return trip, again FSD and basic AP not functioning, and out of the middle of nowhere with nothing happening, my car slammed on the brakes and showed the warning "emergency braking in progress". Thankfully there wasn't anyone close enough to hit me.
I'm hoping I get the update to roll me back because the car is basically unusable with this version. If my safety score comes back and includes that drive, I won't ever get back in the program. Was cool for that one 2 mile drive I guess....