The PXAUX simply plugs into the factory radio (with the model-specific harness) and lets you listen to your ipod through the car's audio system. Of course the trick is to access the rear of your factory radio and then find a place to stash the PXAUX box. Fortunately there is a long cord to give you plenty of options. I do not claim to be an audiophile but it sounds fine to me. As stated, the car audio controls none of the ipod's functions although you can obviously change the volume in both places. It is so simple that it seems overpriced but every other solution that I saw cost more so I paid the price and am happy that it works as advertised.