The plug on the other end is not for audio. It's a special antenna plug (looks like audio though) that plugs into an FM Out jack on the satellite radio. I've installed these on a few cars, you most definitely cannot plug it into the headphone jack of an iPhone.
That's not to say there's not an adapter that allows you to plug it into an iPhone - you would need something plugged into the dock connector or headphone jack that modulates it to an FM signal, then it would plug into the FM adapter which then plugs into the back of your radio. I don't know of any, but there might be one out there. They take some knowledge to install, since you have to get to the back of your radio, and some extra hardware could be required (American and European cars usually need an antenna adapter), but they do work well if your radio doesn't have a regular AUX input.
However, like I said, if you just pick up one of the adapters used for satellite radios and plug it into your iPhone, it won't work.