Comfy

This system is there in every car I have owned. It's possible that it was present in your previous cars but you never noticed / never needed it.
Besides, the locking button from driver door only locks the windows / central locks, not the child locks. If anyone has a different experience please let us know. Thanks.

Oscar2

What we are talking about are the two buttons just below the window controls on the driver's side. Those buttons are how you turn the child locks on and off. If you accidentally hit one of those buttons, then your passenger can't get out.

Comfy

Thanks for the clarification . I was relating to other ( non Audi) cars I had.

John Simcox

In most cars the rear door child locks are activated using a mechanical switch in the trailing edge of the door. Audi has simply made them electric and controlled from the electric window panel. They have also combined them with the rear window switch deactivation, which most cars with rear electric windows also have. Indeed the advantage with the Audi setup is that you can selectively deactivate the rear windows depending on the age and responsibility of the person on each side. You will also notice at night that the illumination of the door release and window switch goes out on the door(s) where the lock/window has been deactivated