The BMW 645CI is the newer designed 6 series by BMW. The 645 has a powerful V8 and on some models comes with the SMG transmission. On the 645, the brakes seem to us to be abit weak and the brake dust is aweful! Our recommedation is to upgrade to Brembo gas slotted discs and a set of Akebono Brake Pads for the ultimate in brakes. The suspension could us a set of Bilstien Struts and a Pro Kit from Eibach.