I have a 2003 A4 3.0 w/ 6 in-dash CD changer...do I also need PHATBOX WIRE HARNESS 4B0-051-735-B and the bracket to install in the trunk?

If I install in the glovebox, does anything else need to be ordered, other than the unit itself?

...not enough room in glove box...unless you dismantle the pbox (metal shroud); it's been done before...search the forum for pix.