I kinda miss the days of an outside mirror being a piece of glass on a stick! Reach out the window and adjust. Now, think about what that mirror really is. Heated glass for starters. That takes wires and a heater pad. 4 way electric adjustment. More wires and an actuator. Electro-chomatic dimming. Sensors in the interior mirror sending signals to the electronics, then to the mirror 'brain' to properly dim the glass. Power-fold. More brain power here, as the unit will only fold so many times in a row to prevent damage (kids playing with the button?) Video camera. Think about all the electronic stuff (wires and brains) needed to tie in all the cameras for top and side view to make a nice picture on the screen.

BMW divides design into four groups. Exterior, interior, powertrain and electrical.

The mirror isn't mostly an EK component (exterior) it's more of an EE (electrical)component now.

The interior mirror is EE. Homelink, EC dimming, compass, video camera (smartbeam), light sensor, alarm indicator....