The regulation calls out 19 vehicle functions which must have physical controls inside the vehicle, with additional requirements about size and usability of the buttons.
Those functions include:
Turn signals
Hazard lights
Horn
PRND gear shifter
Driver assist function, if present
Windshield wipers
Windshield defroster
Power windows
Emergency call system
Power off switch for EVs
Musk’s goal is to eliminate all human input - including the steering wheel. He has said “Almost all input is error. Car should do the right thing automatically.” Removing physical controls is the first step.
This is probably a mistake. But Musk is unlikely to ever admit this.