The 2007 models do not have an auxiliary jack, but DO have the capability to add one to the factory radio.
I wired up my own and it cost me about $10 in parts. Here's a very GENERAL overview.
Thing's you'll need:
3 - Audi Repair Wire Female - part #: 000-979-009 http://www.nsxjr.com/partpix/000-979-009.JPG
-- buy an extra while you're at it
Audi Radio Removal Tools
(4) Audi radio removal keys - http://enfigcarstereo.com/shopsite_s...ND_42_002.html
Solder, soldering gun, etc... or electrical tape if you're lazy.
1 6ft Miniplug (3.5mm) to RCA cable.
Access to a VAG-COM
If you pull out the radio using the removal keys you can see the wiring diagram. It looks like this:
You'll see there are labels for "Aux-L" and "Aux-R". Unplug the harness from the radio and push some new pins (the repair wire with pins attached, they should snap right in) into the holes that line up with what's shown on the diagram.
Also add a new pin by doing the same thing for the "Aux-|||" symbol. This is the ground. You should now have 3 new wires sticking out from your harness. Plug it back into the radio.
Now you can take a standard RCA to mini plug cable and cut the red (right) and white (left) ends off and strip away a generous amount of cable. The inside of the wire is the positive; the metal "shielding" or outside of the wire is negative. Connect the positive of the red wire to the new connection you made on your radio for the RIGHT side; do the same thing with the positive of the left side.
Now you want to connect the negative sides of the white and red (the outside shield) both to the "Aux-|||" wire.
Hook everything back up.
Lastly, you'll need to activate the Aux input through the VAG-COM. Just look around, it's pretty easy to find.
That's it! Now when you press CD twice it comes up "Ext. Source" in the display and you can plug anything you would like in.