I think we need to put things in perspective here.
First, this type of rust is unacceptable. Period.
What we don't know, however, is what Mercedes has done, if anything, about this problem for this owner. The photo is someone else's car, not the person who posted the photo. I can tell you that Mercedes would be working out some type of acceptable compromise with me if that was my car. While this level of rust is unacceptable under any circumstance, we also don't know the history of the car. Did it live in an area of the country where they salt/chemical the roads a lot? While, as pointed out, there is a rust problem with these cars, if you live in the rust belt, you should expect some rust (again, not to this level). You have some responsibility if you live in a rust region to thoroghly wash off your car (yes, and that includes the inside of your fender wells) often. Also, that rust didn't happen over night. Come on. Take a peek under your fender wells from time to time.
Finally, as to the argument that Lexus, Infiniti, etc. are superior, remember that a lot of us (maybe most of us here) have no rust problems and few maintenance problems. I've driven the Japanese competition. They're fine cars. But they don't have that German feel like Mercedes and BMW. Maybe the Japanese cars are for people who never "get in tune with their cars". Turn the key, change the oil, and know nothing else about the car. For those of us who buy a used Mercedes in great shape with no rust for less than half the price of a Japanese car, nobody is going to convince us that "those" cars are a better deal.
