I want to play music from phone through the headphone jack to my car stereos audio line in.

What size cord do I need?
An Amazon link to a specific product would be great.

Walmart sells Aux cords for like $4 standard size. Unless your phone has one of those stupid mini jacks

http://www.amazon.com/gp/product/B00NMD4ZCQ/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
works great, auto connects to phone and lasts a lot longer than aux cords do, a week or so lol.

Ive had the same aux cord for 3 years. Not sure what you do to yours

probably thos ones you find at the quicki marts for $2
i actually bought a good expensive one for my ipod because in those crappy ones gave me weird sound and feedback constantly. $15 for a aux cord and crystal clear

blue tooth and usb. get with the timmes