cbl117 - I got BMW Performance exhaust first and had no pops and crackles. After I got BMW Performance power kit version 1, which is a software only tune, is when the pops and crackles came. BMW also advertises the sound on their website, here:
http://www.shopbmwusa.com/PRODUCT/35...ANCE-POWER-KIT
I'd love to hear a video of your car.