US 2010's and some early 2011's got the base system.
The worldwide base system with no amp .
There were a lot of people pretty upset about this.
BMW reinstated the Hi Fi as lowest level US system around sept of 2010 in 2011 builds
but still a month or two of base system slipped through to 2011 .
They are easily identifiable by the lack of tweeters in the front doors.
The reinstated Hi Fi and L7 system now does not have tweeters in the rear area's.
Also they dropped the pre wiring for a lot of stuff that year like for
the alarm system.