I found this out by reading a Pre-delivery SSM on a 2014/2015 Ford Focus.
Note the info about wheel/tire cleaning products removing material from PVD clad wheels. Don't use anything on your wheels with Hydrofluoric acid in it.
SSM 44731 2014-2015 Multiple Vehicle Lines - Brake Rotor Protective Cover Removal
Some 2014-2015 vehicles may exhibit material transfer from wheel film/hard shell covers which may or may not be visible on the wheel surface upon removal. Cleaning the wheels is necessary to remove any residue. In some cases, residual material may appear to be scratches on the rim flange, but can be removed with the following process: Apply generous amounts of Motorcraft Bug and Tar Remover and allow it to soak on the wheel surface for at least 1 minute. Use a soft cloth andapply moderate pressure to wipe residue from wheel surfaces. Apply Denatured Alcohol as required to remove any remaining residue. Repeat process until the wheel surface is free of any residue.
Note: Hydrofluoric Acid, contained in some wheel/tire cleaners will cause discoloration on chrome clad wheels and removal of chrome appearance paint layer on PVD Wheels. Use only Ford approved products.
EFFECTIVE DATE: 23-SEPTEMBER-2014