Loud Rattle when accelerating

Hello everyone, I'm new to this forum and have really enjoyed learning more about my Prius reading threads in the past.

I have a question that has been talked about before, but it seems like there has been more than one solution. I'll attempt to post a video so that hopefully somebody may be able to assist my particular rattle

 

Thanks for the reply Aaron, the sound is coming from under the dashboard and not underneath the vehicle. My local mechanic couldn't seem to pinpoint the sound either.

My cat needs replacing, which I will in the near future, but I couldn't imagine that the sound would derive from it.

 

It definitely sounds like there's a plastic wrapper caught!

The HVAC was turned off and the noise still persisted. The rattle sound definitely gets louder incrementally as the engine works harder, i.e. scaling a hill or punching the accelerator.

 

Update.

So I finally found a long strip to road, pressed down in the accelerator, I stuck my head out of the window and the noise definitely sounds like it's coming from underneath the vehicle.

 

Thanks Aaron!

I live in California, so these type of cats can't ship to my location. Any advice on how to acquire one? I'd rather investigate how to get one, instead of paying a little over 2K for the whole assembly.

From your experience do these aftermarket cats last? I hear that the life on these things expire after a year or two and need to be replaced again. Thoughts?