I lived with this issue for quite a long time but it was only at cold start until warm up. Now at 63K, I observed it is less noisy at cold start but the rattling keeps going on when the engine is warmed up. Anybody have a similar experience? It seems like the "disease" has gone up to another stage LOL.

I know the turbo is covered by an OEM extended warranty but what are the foreseeing signs this rattling will become more serious and the right time to address the matter with Mini for a replacement?

I also have a few symptoms I am wondering if not associated with this waste gate problem: Recently, I had to replace the upstream O2 sensor and MPG is slightly down from what it should be. Full tune-up has been done at spring time and the car performs flawlessly.