Yes I live near the westcoast of the Netherlands. Some 10 miles from the coast.

Road salt is also used vigorously here whenever freezing night time temps are expected.
I think we've had a just very little frost till now but I know the roads have been 'serviced with salt' a few times already.

I tend to believe the road-salt could be a major cause of this issue, even though I don't recall other cars having these issues.

Maybe when the original black paint on the radiator gets to wear 'thin' enough, the salty moisture kicked up by cars driving in front, can do it's thing on the copper better and dissolve it.


I can even see a copper build-up on the dirt on the engine.
Since this is a fresh engine install (few months ago) and I only noticed the copper 'dusting' on the block fairly recently, I also tend to believe the issue mainly happens during the colder months.