The paint quality in my E55 and my C280 (both 1998, both German manufacture) is OK, but they both show signs of rust bubbles under the paint, and in some tiny spots, the paint is perforated, in larger flat areas of the body, where you simply don't find this sort of rust damage in any modern car.
It has been explained to me that in 1998, Mercedes was changing over to water based paints. Perhaps some more R&D should have been done at the time of the then new paint technology, to retain Mercedes reputation for high build quality. They didn't.
W210's had a reputation for rusting. Fortunately, my AMG E55 seem to have been garaged all of it's life, and seems to have escaped from any structural damage, but it still shows tiny signs of rust bubbles, as mentioned above.
I have since drowned the poor thing in fish oil in all structural parts of the car that I can get at, as it sat on a hoist. All of that stuff is now very nicely dry to the touch.