try furiousmethod.com - it will open a dozen or two windows, that will scare you into thinking it is a virus, but what it does, it looks up the part number through various sellers...

our main sites are RealOEM to look up the part numbers, and the WDS for diagrams... diagrams can be very very very confusing... lol...

i buy my parts (not all of them) from BMW of Fairfax, but not from the counter - i go to their website, place an order with a good discount, and then tell the checkout that i will pick up the part - a lot of times very competitive price for an OE part...

give me a sec, i will get you the as-built sheet...