If it came with a CD changer there are kits you can buy that use the CD changer plug. but I'm not aware of our Jeeps having them. You could always get a new head unit with the usb control and run the cable to your glove box.
What have we got?
We have one heavily armed Recreational Vehicle
I also found the iSimple IS77 adapter ( another adapter like you posted above) that gives you the option of the iPod hookup as well as the 3.5mm aux input ( just have to use an RCA Y adapter to use both)
Look at lock pick see if that will work with your specific deck. It gives an iPod cable out the back you can run into the glove box. Your three letter sales code from the bottom right of your deck would help (mine is RER)
All FM modulators suck, you will not be happy with the sound
"gryph...I have in the past mistaken you for a perverted chitbag...now I realize that I am not chitbag enough. You truly are a king among men.I am not worthy with such imagination." Series 3 Guy - LRO Site
If you end up going with a 3.5mm hookup, take a look at my thread: Flush mount auxiliary input installed
Once you have the right adapter for your headunit, you can easily...and VERY cheaply...install a flush-mount 3.5mm aux input.