I have a 2004 FX4 and my stock radio has a AUX button, but i cannot find where to plug the AUX in at. any help would be greatly appriciated

 

for 2006 and before im pretty sure you had to a PIE adapter inwhich you take apart your radio. In 2007 i think was the first year they put the little plug hole in the center dash tray. I think you can buy one of those trays and install it on your truck but not totally sure.

 

You have to buy a P.I.E. aux. adapter and install it behind the radio. Its really easy and takes all of about 5 minutes. Do a search for P.I.E. and you will have hours worth of reading and ideas of mounts

 

As stated the PIE will give you MP3 access to the aux button. Factory works the DVD player and/or sat radio. You can buy the sat radio tuner off of ebay last I checked.

 

That reminds me, I still have the PIE from my '05 F-150 somewhere...