Bluetooth dongle for car stereo?

[Kyloman]

I'd like to get a new car stereo, but I don't want to pay for the extra bluetooth. Is it possible to use a bluetooth dongle to play my phone through the USB port?

 

[StraightShooter]

I have no idea what a "bluetooth dongle" is, but if the stereo has a USB port, you can DIRECTLY play music though the stereo.
Without something "dongling".