A double heavy duty oil bath air cleaner in my simple dusty plain beige 181.
Not much... the M63 military conversion and the M220 Limited slip differential
Exhaust emission control system and activated carbon container for absorbing fuel vapor.
Support for second generator.
Limited Slip Differential
Eberspächer BN4, petrol heater. These were common in most military 181.
M153Filter system with two oil bath air cleaners. Astonishing, isn't it!!
Reclining seat backwards (only passengerside), sleepingmodus.
Side-mounted flashing indicators (Denmark, Norway).
Yellow headlamps and safety rear view mirror (France).
Additional third mounting-point for front seat-belt (Denmark and France).
Cracking the codes... which options did your 181 have? The m-codes can be found on a little label in the car. I will try to make a list of all m-codes. These are the first:
Speedometer in MPH
all-rubber bumper overriders (on front and rear bumper, available in different styles)
Lockable Fuel Cap.