If it has an external audio source - like a cd changer - there should be some type of adapter to use that as an aux input.

But I don't think aviators had external cd changers. My 03 has an in-dash changer and no auxiliary sources.

I haven't really tried, but I can't think of a convenient way to come up with an aux in.

There is the fm transmitter option, but that is picked up just like a radio station and sound quality can suffer. Plus, if you're in a city you are likely to encounter some interference from time to time.

I have also seen an adapter that connects inline on your fm radio cable, but I don't have any experience installing them, and I don't know anything about the sound quality.

As mike suggested - it may be easiest, and not all that expensive, to just replace the stock unit with an aftermarket source that has the aux input style(s) you want.

Lincoln Aviator Radio

All Lincoln Aviators come with the satellite option, SAT button next to the am fm under the volume knob, or aux/sat in the touch screen radio

you can add an auxiliary input port to the factory Lincoln Aviator radio, using this audio interface

http://www.oemautosound.com/p-45-ford-auxiliary-fr...

edit:: There are stories I think I read in an Al Ghazzali book about those going on a long journey across the desert for instance who used to sing to their camels/asses to make their journey easier for them carrying their load. Plus what mother wouldn't sing a lullaby to her baby? Plus what about the Psalms of David (peace be upon him) - weren't they song/melody? The athan is very beautiful. Bird song is very beautiful. I think to say music per se (this includes song and melody) is haram is too simplistic. If the Qur'an doesn't say it is haram then can we say it is haram. But some music may carry harm. For instance: rock music is connected with the satanic and is said to carry satanic subliminal messaging. Best to stay away from such music and any other of doubt.

What David said or buy and install a new radio it should say MP3 or aux on it.

There is some inexpensive ones out there.

Only thing I can think of is one of those cheesy radio transmitters....you plug them into your phone, and set your radio to a specific frequency, and it will transmit the sound...the quality isn't that great, though.

Something like this..but there's a lot of different ones out there:

http://www.ebay.com/itm/like/140967974556?lpid=82