I have a strange noise on my new to me 2004 JCW w/200k miles - I've listened to every video clip I can find on YouTube and elsewhere of R53 rattles and noises, and I haven't heard any other mini make this noise. It's also hard to describe, but it's very obvious. Kind of like a tinkling/rattling/buzzing sound, but not metallic, almost like a large fly buzzing. Can't hear it at idle, but hear it in neutral when revving or when accelerating somewhere around 2k and above. Doesn't happen when I left off the gas, I can hear it make a "tink tink" noise a couple of times as soon as I let off. Car pulls well, plenty of power. I replaced the air intake hose as it was split, and swapped out the K&N filter for an ALTA filter, and the noise did not change. I just have no idea what's making the noise. Sounds clearly driver's side. Anyone have any ideas? Here are a couple of videos, I really hope someone has heard this before, appreciate any thoughts!

Under acceleration through gears: Revving in neutral: Acceleration 3k+:

 

coming through a s hissing sound (air leak) on the audio, and maybe some metallic rattling sound also.

I'd open the hood and have a friend rev...