[zaroth]

~85% of cars have EDR (event data recorders) which are always recording locally.

NHTSA requires cars with EDRs to record 15 specific attributes. They’ve also considered making EDRs mandatory, but basically didn’t bother since the vast majority of cars already have them.

You need an EDR to implement ADAS features, and some of those are becoming mandatory.

The only thing opt-in is remote data sharing.