I reg. use bimmerspecialist and have used autoparts.ca once. However there are a ton of parts that they simply don't carry or stock. If you're doing a rebuild you're going to need all those odd bolts, etc...
In that case I use Pelican parts for those orders. Takes longer to get here to Canada, but hey.
If you want CHEAP old stock (cheap rotors etc...) check out rockauto.com. They are hit and miss on pricing. Good for new cores on control arms, calipers etc...
09 Jetta CleanDiesel M6 Highline
85 325e M5
07 Honda Shadow Spirit 750