I found this hanging from my 2016 Charger. It was on driver's side, behind the rear wheel. Due to tme issues, I just pulled it and it came off easy and I placed it in trunk. The majority of it was visible so it wasn't hanging on by much. I looked under the car and couldn't see anything similar on the other side. I don't know if i picked it off the street, or it's from the car. I'm hoping it's not some kind of heat shield. Any ideas?

Back side

 

It looks a bit like the insulation that sometimes gets placed on the underside of the body above the mufflers, resonators, and catalytic converters to reduce how much heat radiates into the cabin. You might want to see if you have similar insulation above one of the mufflers and not the other.

-Rod