You can pay someone to do it as well. I went to Houston Car Stereo and had them run it through my aux input, and I paid about $80 and they gave me one specific for Ipods that charges my ipod as it's plugged in...so it never runs out
All the aux inputs are is an inline fm modulator. In other words it the same as the fm transmetter but it connects directy to you fm antennae so you get almost no interference.