Got mine from mazda when I purchased my 2008 5. After researching the available after market thule and yakima models for the 5, I decided the factory oems were just as good and were about the same price.
I used to have a set of yakimas for my acura, and they were nice, but a bit of a pain to take on and off. The ones for the mazda take me about 5-10 mins max to pop on or off.