1) Headrest problems are usually the headrest rack & pinion inside of the seat.
2)Try removing fuse # 9 in the trunk & see if it starts working again.
4)Dome lamp should fade!
6)You will have a MIL light for ASD/ASR if so equipped. Most S420's have either ETS OR ASR. Only diesels & 6 cylinder cars had ASD.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)