loud noise while braking and or coasting

[statultra]

i actually posted this question before, i would like some suggestions as to what this is , on my salvage toyota prius 2005 the vehicle somewhat amplifys the sound of regeneration, and engine noise when braking and decelerating, its odd, i checked the brakes and brake lines, im sure its not the engine, but the odd thing is for example if i am on a hill and theres stress in the parking gear the engine will make a loud noise when your inside the vehicle, like a rattling, when you exit the vehicle running it doesnt make any noise. Its odd.

Simplifying the factors that effect it,
noise comes on when :
slowing down with regneration ( amplification of the whining noise of regen )
slowing down with regen and engine running ( amplificatino of both noises )
reversing on a hill with engine on ( amplification of engine noise )
at idle on a hill with stressed parking gear ( amplification of engine noise )

im not sure what this is, but i have a odd feeling its hte stabilizer bar, or some sort of bushing, im not sure.

If anyone has any insight into this it would be greatly appreciated, the vehicle drives perfect straight line and such, just this annoyance.

- Thanks

Brian