So I'm looking to replace my factory headunit in my 2001 Dodge Durango, because I want to plug an auxilliary input adapter in and hook it up to my mp3 player. I know that there is a factory headunit for a 2001 that DOES have an aux input in back, but the only thing about it that I've been able to find out is that it must have either a "cd-c" or "mode" button on the front, which indicates this. Unfortunately, I don't know what the model number for that headunit is or where I can get one. Can anyone point me in the right direction? Thanks in advance.

 

I'm looking for the same kind of thing, but I think I have settled on a solution. http://www.discountcarstereo.com/detail.aspx?ID=360
This is a factory, I think, part that connects to the back of the stock head unit. It turns the input for the factory available CD Changer (CD-C Button) into an AUX RCA input. From there you can add your own 3.5mm jack, or whatever other adapter you may need for your particular piece of equipment. Part costs $60. Caveat: I haven't done this yet, so I am just tossing around the idea. Hope it helps.