I know not many here use WOT acceleration, but the few who do it regularly, do you hear some rapid popping or ticking? No, it's not engine knocking or preignition. Almost sound like the sound when you brake to stop at low speeds while on a curve, but much louder, over the engine noise. Edit: Sorry, there is thread for that already: Squealing/Rattling noise During Acceleration | PriusChat I actually searched but didn't see it. I saw it right after starting this one.
