does anyone know of an easy, inexpensive way to add an mp3 cable or input into a 2007 911

I have a 1999 911 with no auxiliary cable input. We use an FM transmitter (this one http://www.staples.com/Monster-iCarPlay-Wireless-800-FM-Transmitter-for-iPod-and-iPhone/product_912412) that allows you to play your mobile device through the radio. Its a sucky alternative since there's almost always some static. CNET also has some good suggestions too: http://reviews.cnet.com/4520-10895_7-6262887-3.html

Wonder how much it would cost to replace the head unit with a new generation one. I recently bought the 2012 cayenne with the new generation head unit and the iphone integration is amazing - all your playlists are displayed, your phone contacts show up on the display. Really amazing integration.