I installed the Soundgate aux adpater to the bose, everything works great except I have this loud whine when i accelerate. The adapter didn't have any ground wires but I used a ground loop isolator that has 2 ground wires. I tapped these ground wires to the bare metal of the car. Am I tapping these ground wires in the wrong place? Should I tap them into one of the existing ground wires that goes into back of bose head unit?

 

Ground loop isolator is a bandaid...but anyway, one of the wires goes to the back of the Bose, the other to bare metal.