A near-universal W116 flaw is collapse of the rear-seat cushion padding while the front seats hold up; the horsehair stuffing disintegrates and, left unaddressed, damages the leather above it. The community treats a documented rear-seat rebuild receipt as a major value-add and points to specialists (Woods and Barclays in Georgia) who rebuild the padding while retaining the original leather.
Rear-seat horsehair padding deterioration
Mercedes-Benz S-Class (W116) · cosmetic