Hell I didn't think you were registering too. I don't know about anything specifc for the E60, but I do know about alternatives and I wanna get one for mine. The Phatbox. http://www.phatnoise.com/products/digitalm...ayers/index.php
is a replacement for your factory CD changer and plugs into the same wireing harness, allowing you to use the factory steering wheel and radio faceplate controls of your current car stereo. Even has wireing available for your Audi A4 http://www.phatnoise.com/audi/
It's not cheap (around $860) but read through the details on their site and it looks worth it. This kenwood Keg (available at ultimate electronics and other places like it) is the same techknowledgy that kenwood purchased from Phatbox but I don't think they have the cool factory hookups for the Kenwood.
'The PhatBox Digital Media Player is an evolutionary breakthrough in car audio entertainment. Imagine a factory CD changer with boundless capacity that knows how you like to listen to music, and you've got the PhatBox. The key to the evolution is the ability to store hundreds of hours (or thousands of CDs) of content on a palm-sized hard-drive cartridge. In the car, the trunk-mounted digital media player connects directly to your existing car stereo and puts all that music at your fingertips"
So post a pic of your A4 in the Showroom or Other Autos section. I was gonna stop by your dads and get a pic of it while you were in town this weekend but it was too rainy. Maybe next week if you bring it
just.. by the way.. yuo can get a tiny portable mp3 player (archos etc. size of a hand) with 20 gigs on it for $200. stick that anywhere in the car, glove compartment even. and run a line to the radio under "CD". and you have a 20 gig mp3 player in your car.