Click on any of the wheels in the following link and check the ET.
The wheels you currently have with ET28 and ET18 are the correct ones for a CLS. The spacers you have are just pushing the correct wheels out further.
Mercedes CLS Class Coupe Alloys (C219) - Alloy Wheels Direct
The alloys you see with ET48 and 58 are not designed for the W219 CLS whatever the seller says.
These wheels are actually from a cls that is being broken to parts. This is what os confusing me.