YES! YES! There is such a unit at Best Buy... it's a Dual XDM6400 head unit with WMA MP3 CD, front AUX, AND (the coolest feature) front USB port.
Here's a link:
http://www.dualav.com/receivers/xdm6400.html
I can plug my iPod shuffle or usb drive right into the head unit and it'll play my music straight off of it. I can also plug in my Samsung sat radio/recorder right into the AUX jack on the front and play from that. The CD player is MP3 capable. It costs about $99 bucks! Because I saved so much on the head unit, I also bought a Dual 300Watt amp for $79 bucks and mounted it in the trunk.
Here's a picture of it... mine was blue:
http://www.dualav.com/amplifiers/hires/xpa2100.jpg
It all works great together, but don't expect fantastic sounds from the Porsche... it's just not an audio friendly car.
-Troy