Feedback spurts with Avic N2

Today when I was fooling around with my N2, i kept getting these spurts of noise coming out of my speakers at around 10 second intervals or so. My car was off at the time and it wouldn'st stop. Even if I powered off all the sources, it still came through. I remember it happened once as well when I tried rolling up two windows at once.

When I started the car back up, it was fine again.

Any thoughts?

Thanks for any replies.

I narrowed down a bit. It seems whenever my car is at idle or off, the noise happens every few seconds. When I am driving and come to a stop, everytime i press the brake pedal, it makes the noise. It also makes it if I engage any other electrical devices such as power windows or locks.

Any thoughts?