USB input options for stock stereo?
 

Has anyone figured out a way to add USB input to the stock factory radio (non-bose)? I found this adapter below, but my stereo does not have a CAT or SAT button. Nissan Infiniti GROM USB/iPod interface adapter

OR has anyone tried installing the upgraded (6 disc changer, MP3 compatiable, etc.) factory radio in place of the basic radio? Not looking to add an aftermarket radio if necessary.

Thanks