BMW introduced the 645Ci as the launch model of the modern 6 Series coupe family in 2004, bringing back the 6 Series nameplate after the original E24 era had ended in 1989. The 645Ci was positioned as a large luxury sports coupe, with a matching convertible joining the lineup in the same model year and marking BMW’s first modern 6 Series open-top car. It was the flagship 6 Series variant at launch, intended to blend grand-touring comfort with a strong performance image and the brand’s traditional rear-wheel-drive character. The model is closely associated with the first-generation E63 coupe and E64 convertible body styles, which defined BMW’s return to the segment.
For the 2004 and 2005 model years, the 645Ci sat at the top of the range before BMW revised the car for 2006. At that point, the 645Ci name was replaced by the 650i as part of the same generation’s facelift and powertrain update, ending the 645Ci’s original production run. Because the nameplate was used only during that single continuous era, the 645Ci is remembered as the short-lived but important relaunch model that reestablished BMW’s 6 Series in the modern lineup and set the tone for later 6 Series generations.