If it may help, I have a complete set of E55 AMG calipers matching w/ front C/E63 360mm girodisc rotors (had to put a pair of 2mm shims to adjust the front calipers' offset) and a pair of CLS rear rotors that match the parking brake drums of the GLKs - did all the research on diameter, height, thickness, druams diam. etc checking ATEs rotors catalog, very user friendly; liekly any C63 or other W204 front calipers will be a practical bolt on to our GLKs; Ah, do not forget to change the brake booster to ensure the bigger calipers sopping poower is noticable at your pedal;