its a very stout built car and is very nicely packaged together. Its a bit cramped from the inside in the rear seats but they are great seats nonetheless, the front seats are fantastic (better than my W210). The A/C in the early models are R12 based and work great with R12 but wont work good with R134a, the later models came with R134a components and a larger displacement compressor and twin condenser fans. The A/C is nice on those but not W140 level nice. The last models came with a cabin air filter and its very welcome as it keep the evaporator coil clean.
The wiring is very simple and analog type on the W124, but do read out how its laid. Its easy to mess it up. The sunroof (if equipped) is the most weirdest and complicated design you will see, the motor is tucked in the boot on the left of the car and long cables run to the front to pull/push the sunroof open and closed. Many parts are plastic and they will break with age.
The automatics are the oldschool full hydraulic MB units. They are direct drive systems meaning the last gear is 1:1 ratio also meaning the rpms will be high on cruising on the highway (great for revvy engines as they enable you to pass easily) - the rear end gearing makes a great difference though. They are very complex internally and are quite stressed so you have to keep up with their maintenance schedule if you want them to live - they take cheap dexron II or III ATF. And also make sure they are adjusted correctly.
the ride comfort is there when its in good shape - all bushings in perfect condition and tightened correctly - it has a feel that you wont get in another car. The steering is a bit lazy as its a recirc gearbox type, extremely long life but a bit "numb" - the RHD boxes are very low in numbers globally so getting parts for them is very hard.
servicing them is not too bad, read the manual first and then proceed, dont try to "japanify" it or approach it with a corolla/civic repair way. It will bite back.
