There is a dealer installed kit available, it's called the aero kit. Here are some pictures (just front lip and rear apron).
http://www.e90post.com/forums/showthread.php?t=23522
Only a few guys on e90post have ordered the whole kit from the factory since it tends to be expensive (~$3k), you can get the front lip unpainted for $385 USD and have it painted and installed yourself. Not sure about the rear, most guys just do the front.
There is also the M-kit, but it's only available in Europe right now. Pics:
http://www.e90post.com/forums/showthread.php?t=35579
There is also this, but it is not factory, it's aftermarket.
http://e90post.com/forums/showthread.php?t=46830
I'm going with the aero kit lip (have it, just need to paint/install) and the rear from the aftermarket kit.