Will it work: Delphi FM modulator for AUX in?

Howdy everybody. I found out about the a couple of days ago. Basically, it connects between the car antenna and the headunit to give an aux in for XM satellite receivers. it plugs in to the antenna port on the headunit and lets you listen to XM on one of the FM channels (88.1 for example). I've done some research, and I cant figure out if it would work as a normal aux in, not just XM exclusively. It has a stereo miniplug, so i think it could work, but i want to know for sure before i buy (theyre about $35 new). if anyone knows anything about it, i would love to know, as well as how you like it. thanks!
-ed
PS, i know a guy that can tell me, but its 12AM, so i'll have to wait. i'll post back if i find anything out, cause i have a feeling some members might be interested in this if it works