I am looking at using the Trip Tune (or some other device) for my 06' F150. All I want to do is play my MP3 player audio out (headphones) thru the radio. I still do not understand, will the Trip Tunes plug into the "AUX" input on the back of the radio (using the AUX Push Button on my radio face) or is it a antenna adpter that i must use the FM radio tuner? Any help would be great!

Thanks