Are you refering to the rubber refills or the wiper assemblies themselves? Why use parts that may not fit correctly. Parts Source carries the Bosch wiper replacements or you can get the BMW rubbers refills (rubber blade) at the BMW dealer. You slide the old refills out and slip the new ones in...takes only a few minutes (depending on your mechanical dexterity).
The metal support strips are knotched which allow you to break them off to the correct length, and you can cut the rubber with scissors or a knife. So don't toss the old blades until you get a chance to use them as a template for the correct length.
Here's the BMW part numbers for the BMW refills (rubber blade), you want to specifically "ask for" if you go to your BMW dealers parts dept (they're different than the part numbers you'll see on realoem.com and the other online part databases):
61 61 0 154 441 - front (left/right) wiper blade refills
61 61 0 154 440 - rear Tailgate wiper blade refill for Touring (wagon)
Additionally, here is a thread on BF.C that I contributed to that you should read, you should know what you have before you decide to buy anything.