I have had good luck with www.shopautobahnparts.com for dealer only things like the cover for the rear seatbelt that also holds down the rear seat (72 11 8 149 192). They used to have the parts diagrams on their site. You could also put in a BMW part number and it would bring it up with the price. Help me pressure them to get it back online.
Here's the message I got from them when I asked when they were going to be back up:
Ryan,
Sorry, not any time soon. Have you called David
Lanford directly?
He's a great guy and can get you anything you need
over the phone.
His direct line is 817-390-3311
or toll free 800-433-5602 ext 311.
Thanks for emailing.
Kind Regards,
Derek West
Internet Director
autobahn Motorcar Group
817-390-3827 (direct line)
http://www.shopautobahn.com
derek@abahn.com
For non-dealer type parts, I go to a guy here in Houston that usually deals in Volvo parts. He normally is comparable to the online guys (when you account for shipping) and can have the parts in a couple of hours. I can post his info in anyone wants it.