Hello Ben and welcome to Xj-Talk.

Josh is correct there will always be a delay with using Bluetooth in the JK's and especially the ones with that U-Connect system. The new Rams have the 8.4A U-Connect in them and they do work better but there is still some delay.

You are correct that if you feed the audio through the usb port in the dash the audio delay should go away and on top of that you will get better audio quality. Good luck!