Personally, from what I've seen and read about the roof blisters, I think there's a far higher percentage affected than 5%.
Some people will keep it to themselves.
You are quite right.
Unless people with roof blisters post, we will not know how many vehicles are, or have been, affected.
Intuitively, the number feels much higher.
However, if you divide the number of reported problems on this thread by the number of registrations it was under 5% just before Xmas.
Clearly the actual percentage is higher because not everyone reports on this forum.
Whatever the figure, it’s a significant percentage and it seems to be getting worse. MB should be doing more.
Alarmingly, the problem is being identified with relatively new vehicles, which indicates MB are no nearer to curing the problem..