Is there a port in the back of a stock radio in an '07 Pontiac G6 to plug in a...

[Juddro]

...standard mp3 jack? I'm trying to find some other way to get my mp3's on my iphone to the stereo. I have an fm transmitter but the buzz is super annoying. There is no outlet in the interior of the car that I'm aware of, but I know some factory radio's have one in the back. Before I go taking it apart and probably breaking something, does anyone know if there is an outlet there? Or do you know of a better way to play mp3's? Thanks