I had a Samsung Galaxy S3 (returned it for the iPhone 5) and thought that is was not compatible with my 2007 335i with IDrive. I found out that it does pair and work. I think the phones bluetooth is very week ass i could only get it to pair by holding it under my steering wheel. Even after I had it paired it would not connect unless I held it under the steering wheel. I think the unit in the car is fine as my iPhone 4 and iPhone 5 work perfect in it.
Just thought I would share what I found.