Good: Basic, Entry-Level Option
Wired FM Radio Connections: br>
This device also plugs into the iPhone's headphone jack for playback through an FM frequency on your dashboard radio, but it doesn't need to be an open frequency. Because the device is hardwired into your radio.
Vehicle-specific or Universal Aux-Input Connections: br>
The beauty behind this option goes beyond a higher quality sound you get from a direct connection (via aux input) to your existing factory radio, but it's also ideal if you want to integrate other devices such as an Android phone, tablet, or other media device.
Better: Bluetooth audio streaming
Connect your iPhone to your Stereo without Wires: br>
If your car stereo deck supports Bluetooth audio (A2DP), you can connect your iPhone to your car stereo wirelessly. Start by pairing your stereo with your iPhone through Bluetooth settings on both. Follow the prompts on both devices to complete the pairing. If you’re asked for a PIN, 0000 usually does the trick. You’ll only have to pair your devices once, and you should be able to use both your audio streaming and hands-free calling services. You’ll have some dash-board control, but no song title or album art in the display. Keep an eye on your battery, Bluetooth streaming tends to eat up the power. Having a phone car charger on hand while streaming bluetooth audio is always a great way to keep your battery full.
If the stereo deck doesn’t support Bluetooth audio streaming, all is not lost. You can attach a Bluetooth accessory to an aux input cable that does.
Best: Installed, full control & best sound
Vehicle Specific Direct iPhone Control br>
Like the aux-input, this option features a direct connection and, therefore, a higher quality (if not the best quality) sound. But the connection is via an iPhone-specific cable rather than an aux-input via the headphone jack. You enjoy complete control of your iPhone on your car stereo dials or steering wheel controls. Song title, artists, playlist – for most cars, it all shows up on your stereo display. You'll need a vehicle or radio-specific kit.