Working factory infrared remote key fobs are treated as essential and effectively NLA; Chinese replacements reportedly do not work. Missing fobs materially dent value and complicate ownership, though commenters note Mercedes has floated a new run of main keys and third parties can cut keys at roughly $150-$500 (valet vs full). …
Infrared key fobs are unobtainable
Mercedes-Benz S-Class (W140) · ownership