Vehicular door lock operation system and vehicular door having the same

A vehicular door comprising:

• a door outer panel;
• a door inner panel secured to an interior surface of the door outer panel;
• a trim secured to an interior surface of the door inner panel and constituting an inner profile of the vehicle interior;
• a door lock device having an opening member and a locking member, the door lock device being secured to the interior surface of the door inner panel and positioned between the door inner panel and the door trim;
• a door lock operation system including a handle mounted on the door outer panel and linked to the opening member of the door lock device, a door key cylinder linked to the locking member of the door lock device, a first connecting member and a second connecting member, each of said first and second connecting members having first and second ends, said first end of the first connecting member being connected to the handle, said second end of the first connecting member being detachably connected to the opening member of the door lock device, said first end of the second connecting member being connected to the door key cylinder, and said second end of the second connecting member being detachably connected to the opening member of the door lock device;
• the door key cylinder including a rotary case, the first connecting member passing through a portion of the rotary case and being supported by the rotary case;
• and
• the rotary case passing through a through hole provided in the door inner panel and being supported on the door inner panel.