Where is the plastic black wing nut on rear lights a Ford Fiesta mk6?
The plastic black wing nut on the rear lights of a Ford Fiesta Mk6 is located on the inside of the boot (trunk) lid. You'll need to open the boot to access it. It's usually held in place by a small plastic clip that's part of the light assembly itself. You'll likely need to gently pry the light assembly away from the body of the car to access it.