There's some Auxiliary device designed by USASPEC. All device also gives you the opportunity to connect a ipod/iphone...so they both have 2 interfaces.
Personally I have the PA11-HON2 for my TL 2004, simply enter your car makes and models and you'll see which device is suitable for you car.
http://www.usaspec.com/page.php?PageID=19
Since the Mac mini audio card is not the best, I also bought this unit to improve the Sound quality :)
http://us.store.creative.com/Creativ...B000IZ96LQ.htm
Hope it answers your question !!
Good luck on the install!