Check out the Kenwood 6990HD. Someone did a comprehensive post on it in the audio forum. I don't have iDrive, so that will most likely be my next upgrade.
Montego Blue Metallic e92 6MT
|| BMW Performance SSK Kit || Charcoal Delete w/ K&N Drop-In || CDV Delete || Custom Clutch Stop || (3) Stage Manifold Swap || Stage 2 Eurocharged Tune (