[In addition, this would have had significant play in it for some time, leading to noise which would be noticeable to most drivers when on the road, and easily

[In addition, this would have had significant play in it for some time, leading to noise which would be noticeable to most drivers when on the road, and easily noticed during any kind of worthwhile inspection (such as the MOT in the UK) - not sure if the state in question has a mandatory inspection?] True. I've had to replace a few lower control arms on various cars due to loose ball joints. In all of the cases, the car made terrible sounds during normal driving long before the ball joint was actually loose enough to pop out. It was always very evident that something in the wheel was loose. Of course, anything can happen... [Components such as this are usually sourced from sub-contractors, who produce them by the thousands/millions without issue, does anyone know if Tesla makes these themselves? Seems unlikely to me.] I agree. I doubt that Tesla is making their own ball joints. It seems like to much NRE considering there are tons of off-the-shelf options available.