so the newer Ipod touches and iphones have a 4-pin 3.5mm jack.

this allows the remote on the earbuds to control playback like play,pause,rewind,skip.

some reference pictures:
http://adroitobs.files.wordpress.com...headphone1.jpg
http://img299.imageshack.us/img299/9...torplug4ap.jpg

this is a long shot but has anyone tried connecting a 4-pin 3.5mm M-to-M into the aux to see if you can control song playback though the buttons on the car console/steering buttons.

just askin :P

 

your best bet is to not use the 3.5mm aux input, but instead an OEM interface ipod adapter that allows for charging and playback. Essentially they come in two flavors. One can plug into a cigarette lighter providing power to the ipod via USB and extract audio for the aux input. These are available on ebay cheap. The second is from PAC-Audio or USA Spec and will be more expensive but are much more reliable and cleaner as they wire into the rear of the OEM head unit. Depending on the radio model you have, you may even gain control of the ipod and display of the artist/track.