Some car stereos use a mini-USB AUX port to connect to mobile devices and play music. Unfortunately, Apple's iPhone accessories do not natively support this type of audio connection. However, you can purchase third-party cables to connect an iPhone 5S and previous generation models to a mini-USB AUX port.

A Two-Piece Connection

You will need to purchase two items – a 3.5 millimeter AUX cable with two male ends, and an AUX to mini-USB converter with a female AUX end and a male mini-USB end. Plug one end of the AUX cable into your iPhone's headphone jack. Connect the loose end of the cable to the converter and plug the mini-USB end into the port on your car stereo. Select your stereo's "AUX" mode. Play a song on your iPhone and adjust your car stereo volume until you can hear the sound coming from your car speakers.