The AMI has a proprietary connector and a short cable must be inserted in it. You can choose from either an iPod, USB or an "MP3" (aux analog input) cable at delivery. It costs about $50 to buy an additional cable.
The USB cable gives you a female USB connector and you can plug whatever you want in it. One of those USB interfaces for SD cards should work for you if you want to move your music around. From my experience however, it's inconvenient enough to reach into the armrest to pull stuff out every time you get out of the car so you probably won't want to move your music from car to car.
I haven't tried it since I already had an iPod but I was tempted to put in a small USB hard drive just for giggles. I gave up though, I chose not to pay another $50 for a cable just to prove that it works.
If you do get the Q7, let us know how the USB setup works.
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2003 BMW Z4
2005 Volvo S60
2008 Audi Q7
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