here is the site for one
http://www.theistore.com/ipod2car.html#
just take your car to any car stereo installation place they will do it for you. the kit usally costs around 100 bucks (im sure you can find it for that) and it just plugs into the back of factory car stereo so no harsh mods you need to make. i got mine from best buy and had everything done there.