Hey everyone, I’ve started to notice my car when reversing I hear something metal is loose. I haven’t fully investigated why taking off the wheel but I was wondering if anyone has experienced something like that. Side note I changed the brakes months ago and here is a vid of it

 

Could the #1 or #2 rear brake back plate have bent at some point & now it rubs against the #4 rotor?
Parking Brake Shoe - 2003 Acura CL 2 Door SPORT KA 6MT (acurapartswarehouse.com)
Rear Brake - 2003 Acura CL 2 Door SPORT KA 6MT (acurapartswarehouse.com)

 

Is the sound present if the car is moving in reverse, but you've put it in neutral?