Go to
www.realoem.com and plug in your vin or build data.
US Spec cars all have Klima Automatic (Automatic AC) as opposed to the manually adjustable AC that the euro and some Canadian cars get as standard equipment.
Here is my DIY that might help you understand what all is involved with replacing the filter.
135i air filter replacement DIY...
http://www.1addicts.com/forums/showt...air+filter+diy