Though it has recently expanded its line to cover a broad range of vehicles, BMW has historically been known for its sports sedans. Its coupes and convertibles date back to the late 1930s, however. They started with the beautiful 1938 327 Coupe with sweeping fenders and available two-tone paint. That was quickly followed by a specially built 328 coupe that won the prestigious Mille Miglia in 1940. For most Americans, however, this new BMW recalls coupes of the mid-1970s: the 1968 2800 CS Coupe, the 1975 3.0 CSi, the 3.0 CSL, and the 6 Series cars that debuted in 1976. The highly regarded 635CSi was a member of this last-generation 6 Series. And the 8 Series coupes of the early 1990s are also considered part of BMW's big coupe lineage.

Now, a decade later comes this new line of 6 Series cars. The 645Ci coupe and 645Ci convertible models are essentially hard top and soft top versions of the same car. Bristling with the latest in technology, they are based on the superb new 5 Series chassis but are not simply two-door versions of the sedans. The 6 Series cars are modern GTs, or Gran Turismo cars. They offer greater luxury and comfort than the Z4 sports car, yet with higher performance, more agile handling, and sportier styling than the 5 Series sports sedans. The 645Ci Coupe and 645Ci Convertible each qualify as an ultimate driving machine, yet can be driven all day in perfect comfort.