Sounds a lot harder than two plastic pieces under the hood coming together. Not sure what dB you used to record the video's audio, however. Seems really loud in there - like metal-on-metal contact with compression of the suspension or up/down movement of the chassis.I decided to pop my hood and noticed that two plastic piece were rubbing against each other on the driver side of the cowl area. I put a piece of sink rubber gasket in between the two plastic, I think that took care of my clunking issue, at least I hope so.
Good to hear you are no longer getting knock, though! Congrats - but please do report back if it emerges again.