As I understand it, there is one brushless electric motor driving the steering with a toothed belt. There are two independently powered controllers that feed the motor. Brushless motors can last a long time and perhaps the controllers can sense degradation in the motor before it fails but there is still only one belt and it seems like it will always be operating at the same places on the belt unlike a timing belt which rotates continuously. Level 4 and 5 autonomous driving should require "fail-operational" capability which means safe operation will continue in the presence of any component failure. Perhaps motor degradation will be dealt with properly but I worry about the belt. Maybe they will require mandatory replacement after certain time in service before autonomous driving will continue to be enabled. Thoughts?