A 2020 Model Y with FSD almost drove us into a big rig, then an overpass support, on a test drive last fall. The culprit was, best I can tell, a road seam in a perfectly well-marked and lined divided highway on a nice sunny day. The same seam does not baffle the X near as badly, but it still occasionally confuses it.
It's not an old cars problem. It's a humans are hard to replace problem. And we don't trust machines to do things. (See e.g. the painfully long period of time between perfection and adoption of auto GCAS)
As you might imagine, my X does not have the $10,000 FSD option, nor am I an Elon's Promise Fanboy Club for Men $200/month member either
I think Tesla and the rest of the auto industry with the possible exception of GM with Supercruise is doing a real disservice to autonomous vehicles with the way they're going about this. I think it's setting adoption of the tech back by decades to facilitate hastening development and perfection of the tech by a few years. For every bogus story of somebody tricking the system and playing a stupid game and winning a stupid prize being blamed on Autopilot or FSD, there are 10,000 stories like mine of their Level 2 equipped car doing some dumb bullshit and eroding trust. I have about one WTF moment per week depending on whether the software version I'm on is an improvement or a step back...and until Autopilot is as good as I think it should be, I'll not be convinced FSD with fewer constraints and more variables is going to work safely enough for my family.
YMMV. And I freely admit Autopilot is the best Level 2 system I've ever used. That doesn't mean it's good enough to call Full Self Driving or give me any hope such a capability will come anytime soon. What a fiasco that marketing meeting on naming the upgrade package for the adaptive cruise suite has turned out to be...note to any time traveling Tesla execs who read this and then travel back to 2011, just call it Autopilot Plus next time. Also, door frames are worth the money.
*stares at X order website to see if time travel is real*