I've read this entire thread hoping to find something related to my 2012 L99 and have not.
Honestly, after +24 years of military sevrice my hearing has taken a hit. My wife, however, does not miss a thing...thankfully.
It was she who brought to my attention a slight rattle occuring just after accelerating from idle. To validate her claim our daughter has heard it also.
I purchased the 2012 new 2 months ago so it is still under warranty.
Has anyone had this issue on 2012 L99?