Need Help With a Stereo Antenna

I don't live right-- I went to the local car stereo shop and tried to explain to them what I was trying to accomplish. I would have gotten frustrated, but TrailBeast and I already had a "who's on first" conversation last night so the one day wasn't so bad. So after I finally got the fellow to separate FM/AM connections from GPS and satellite connections in his thinking (thank you TrailBeast) he finally picked on the part about me trying to use a 2007 Chrysler 300 low profile antenna. I re-asked the question, "will this antenna receive FM signals?" and how could I tell without hooking it up, since I haven't bought the head unit. He said that GPS and satellite antenna cable connectors are entirely different than the standard FM/AM coax connector. So if it looks like an FM coax connector its most likely is.

Monday I'll go to my fabricators shop and retrieve the 300C low profile antenna, go on to the stereo shop and try and confirm I have an antenna that will work as well as fit in my 4X4X6 dash opening. I'll keep you all informed. Meanwhile there's cold one in the box waiting for me.