Well after another week of running glass packs I got tired of the drone. I picked up a set of 4.8is mufflers over the weekend and will install monday.

Also investigating a metallic sound which I hear sometimes if I push the clutch in too quickly when accelerating. My friend who owns a repair shop specializing in BMW felt the front driveshaft for play and thought it is the culprit. He has installed a longer shaft on another customers car and is recommending that for me.