I just got a 2015 grand Cherokee Laredo with the 5" screen. The audio is horrible. I was going to add my subs and amp from my old car but I'm not sure if I should. My question is, is there a pac adapter for the stock headunit they sell or do I have to use a loc? Or which would be better to use? Or should I not waste my time and start with replacing the door speakers first? There's no way to put in a aftermarket headunit in place of the u connect correct? Thank you