Stranges noises coming from the rear

So I'm trying to figure out the two sounds that come from the rear of the car when a load is applied to the rear axle. The first noise sounds like someone lightly whipping cables against sheet metal, and the other is just a short squeak. I hear these noises only when: after braking (i.e letting go of the pedal) or when I start to accelerate. So obviously it only happens when a force is being push downward on the rear.

I have: brand new rear brake rotors and pads, brand new Moog end links (fully greased), and the springs/struts do have over 100k miles on them but they don't seem too bad.

I'll try to take a video of it if I can later.