Depends on your build date (10/10 or later, or 03/11). 6NR was an available option after March 2011 however if you have an October 2010 through March 2011 buld you can upgrade the hardware here:
http://www.bimmer-tech.net/shop/bmw-...drive-retrofit. Depending upon the software level you are at you7 may need the FSC code which is a couple of hundred bucks.
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2011 535i xDrive, Dark Graphite Metallic, Veneto Beige Dakota Leather, Technology Package, M Sport Package, Executive Package delivered Christmas Eve '10, Mods - quad tips, 20% tint, JB4.