On a 2021 S model I see option S5AT Driving Assistant Plus. What would this include?
Good question! A BMW document from 2022 describes Driving Assistant Plus as:
ACTIVE CRUISE CONTROL WITH STOP & GO FUNCTION: adjusts the speed of the vehicle automatically, if necessary, to a standstill, to maintain a safe distance to the vehicle ahead. Maximum speed is set by driver.
SPEED LIMIT ASSISTANT: system detects changes in the speed limit and driver can update the Active Cruise Control set speed to this new speed limit by pressing the "Set" button on the steering wheel.
LANE KEEP ASSISTANT: supports drivers by warning them if they are unintentionally straying from the lane using lane departure warning in form of a steering wheel vibration, and a steering intervention that pulls the vehicle back from the lane marking into the lane.
STEERING ASSISTANT: Supports the driver in keeping the vehicle in the center of the lane using the lane markings and the vehicle ahead while providing an acoustic warning reminds the driver to keep hands on the wheel.
U.S. i3's don't implement Lane Keep Assistant, Steering Assistant, and probably not Speed Limit Assistant. I believe that option 5AT Driving Assistant Plus is included in the U.S. Technology Package. In an i3 with the Tech Package, the speed limit is detected and displayed on the instrument panel, but I don't believe that pressing the ACC "Set" button changes the ACC set speed to the detected speed limit. I'll have to try this.