2 ms·

This entire treatise presumes not using one switch, two locks. Cars seem to have no trouble with this.

• bdamm 8y ago
  Electronic locks was not a thing in 1900. Old cars with manual locks did indeed have the cases where the driver reaches over and locks the passenger door, when the passenger forgets to lock it themselves. And users of old cars will remember the "open front door, reach inside and unlock back door" maneuver.
  • KayEss 8y ago
    Central locking: if you're in the centre of the car yu can lock all the doors.
  • user5994461 8y ago
    Cars in 2000 still had that.