Metallic rattle in reverse

Pulled the car out of the garage yesterday to drive to work and noticed that it makes a loud metallic rattle sound when accelerating slightly in reverse. It only makes the sound in reverse and when giving it some gas. I thought it was a piece of heat shielding making contact with the exhaust somewhere so I checked but didn’t see anything. I’d burn this damn car if it were not paid off!

https://youtu.be/TlXn6NWexlM

So I figured it out this past weekend. The rear (post cat) O2 sensor cable became dislodged from the little metal clip. This resulted in the plastic piece on the cable that is used to attach to the clip to rattle onto the metal shielding when in reverse. Took a while to figure it out but that was it.