[itznin]

I had my sunroof fully open and every slight bump I hit it was making a terrible rattling sound.

I closed the sunroof and the rattle went away, reopened and the rattle came back.

During my drive I made a few stops and it went away eventually.

Curious to know if anyone else has come across the same issue.

[Broken1]

One of the rubbers that hold the sunroof in place might have disloged itself. It can happen if someone tries to open the sunroof before the shipping material has been removed.

If it continues, take it to a BMW dealer, and let them hear the rattle. They will then need to remove your sunroof (and headliner) to fix it :P

[itznin]

What do you mean by if someone tries to open the sunroof before the shipping material has been removed?