aux input on factory unit

[drcworld]

Can this be achieved relatively easily like the one in this ebay listing?

http://www.ebay.com/itm/Chevy-Silverado-3500-2000-AM-FM-CD-Player-Truck-Radio-w-Aux-3-5mm-iPod-mp3-Input-/321463609958?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AChevrolet%7CModel%3ATahoe&hash=item4ad8b96a66&vxp=mtr

:superhack:

 

[NytmareK5]

There are several companies that sell modules for this. Runs about $100.