Do you have the cd changer? If you don't, you may consider using one of these. The sound quality would be greatly improved over fm modulation. Look at the AUDI-AUX
http://www.pie.net/sec12sb1j.htm
For any others reading this, find your car's adapter here:
http://www.pie.net/catsec12x.htm
Pie has been making these things for quite awhile now and they are quality pieces.