I discovered a similar fault with my 430d last night. I bought the car in June and I believe the warranty has just expired as its on a 2015 plate. My problem is slightly different however, as I have got water dripping down from the roof on the drivers side, particularly when i brake hard.

Has anyone experience anything similar?

I’ve also had the problem with the roof leaking when breaking hard or cornering. The car has been into bmw twice and had the roof seals replaced twice, the leak has actually got worse. It’s with bmw again at the moment, I’ll let you know if we get any solution.