Could-a, would-a, should-a: What if the 3-Series Coupe looked like this?

Design sketches of new cars are always more exotic than than the actual production cars that follow. But an official sketch of the recently-introduced 2007 BMW 3-Series Coupe caught our attention. Ignoring the exaggerated proportions and massive wheels, there's something else different about this car. We're particularly fond of the 6-Series-like roofline shown in the sketches. BMW is believed to have flip-flopped between calling the car 3-Series or 4-Series, and this image looks like it was penned with the latter scenario in mind. Would a 4-Series with a truer coupé roof have been a better choice? Have a look after the jump and make your own decision...