Prius just started vibrating in the dash area

So I added a video of the vibration... The car's got about 164,000 mi and seem to run fine for the test drive and the drive home and the first day my wife drove it

However it started vibrating and the vibration kind of reminds me of ping or spark knock?

I read several different things, several suggestions, some people have suggested that it is simply a vibration in the dash

Others have suggested that a heat shield is vibrating

Somebody had also suggested that what may be happening is the VVTi Cam oil screen might be plugged causing a ping situation

And still others have suggested that or maybe some problem in the valve train of the engine I'm not really leaning that direction has the engine seems to run all right

I guess one way that I could check to confirm that it is spark knock would be to put high octane fuel in it and see if the problem goes away

It is interesting note that it was not doing this then we put a nearly full tank of gas in it A solid 9 gal