I am about to buy a new headunit for my car, but I am wondering which kind to buy. I want to be able to play music (stored on phone/Pandora/Spotify) from my Dinc2 through my car speakers. I know buying a car stereo with AUX input is the simplest and most affordable way to do this, but I was also exploring other options. Has anyone tried using a USB connection? Or, has anyone tried playing music through a bluetooth connection? Bluetooth, although most expensive, would be nice because there would be no cords. Also, which one has the best sound quality?