I was using my iPhone but have since switch to an iPod Classic 160GB. It works flawlessly. The startup times are instantaneous, and the playback is perfect, and it allows me to play Apple Lossless, which the built in player in car does not play. It also sends cover art. The only thing that would be cool would be if it played video when the car was stopped.

I bought a short black USB cable and it keeps the center console clutter down.

As ukwildcat said, the USB in the center console turns off after about 2 minutes. Strangely, though, it cycles back on after a 30-60 seconds, and seems to go through that cycle a couple of times, and then seems to turn off for good. It turns on immediately when the doors are unlocked, which probably helps with the playback speed.

The only downside I've noticed is that the car does not remember the iDrive state when I turn it off. That is, when I have the satellite radio on with navigation showing and turn the car off, when I turn it back on the car goes right back to playing satellite radio and showing the nav map. With the iPod, it goes right back to playing the last played song in the last played playlist, but takes me to the main menu rather than to the map, where I left off. The split screen display is often changed as well (I usually keep it on entertainment, but for some reason it goes back to vehicle info).

Otherwise, it's great.