I currently have a 2006 F-150 with a 2007 audiophile radio and the line-in tray that I added. The radio is starting to act up (sub cutting in/out and radio goes into initializing mode almost everytime I start the truck.) I am now looking at possibly buying a nav head unit but have some questions. In order for the line-in tray to continue to work, does only the 2007 and newer head units support that option like the audiophile ones, or can all nav units be programmed to work with a line-in option? Also is there a certain year or model # that I should avoid or can all be compatible after programming?

 

So you want a factory nav unit, or an aftermarket one? If aftermarket I know you can use the AUX-IN line of the new HU and butcher the cord and solder it to the pigtail of the tray plug, it has been done before on here.