Yes (and I don't even seem to have dealer problems). In fact my most memorable failure was around 1983/4 in the supposedly tank-like W123 (200E).
With only about 2000 miles on the clock I was poodling down the motorway in Kent one fine summer's evening on my way to Paris. After some horrendous noise I came to a halt (in a service station) and, in short, when help came a blown-up engine was diagnosed. After ringing round for ages I was taken to Hertz to get a car with which to continue my journey.
(Unfortunately this coincided with the German metalworkers strike and, as there was no replacement motor in the Merc supply chain, I had to wait over two months for a replacement. I had a rental BMW 320, half paid-for by MB UK...there were no 190s in those days, the deal being that I should have a car one class below mine.)
Soon after the engine was fixed I drove to Germany and found that, towards the end (fortunately) of my journey I kept having electrical failure.... the local MB found a screw in the distributor...They said they considered this so serious that they would report it to HQ...
Oh, and BTW, the evening of the day I took delivery of the car I drove out to a pub with a girlfriend to celebrate. On return to the car park I found that the central locking had failed....
Win some, lose some.
DAS
For direct contact replace nospam with schmetterling