I have a Kia forte, which has blue tooth capability, but unfortunately it is only for phone calls and not music streaming.
Kia is idiotic and does not let you use the apple plug to connect directly to their USB port in the car. You have to either buy their cable for $46, which is only a foot long, or use a regular aux cable.
I found an awesome device on amazon called tunelink by a company named new potato technology. It uses the aux connection and plays music over Bluetooth so the sound quality is great and I don't have to have any cords connected unless I want to charge the phone as well.
I can't recommend this device enough to people. It is AMAZING! It's also an FM transmitter in case your vehicle does not have an aux connection.
I love it because it has an app to go with it which allows you to set your phone up where you get in your car and as long as BT is on it automatically starts playing your music over the car stereo. So I don't even have to take my phone out and go through the settings menu to pair it. This along with a jailbroken iPhone and either sbsettings or intelliscreenx quick settings makes using your phone in the car to play music easy. Just turn BT on before you walk out your door!