A midst insincere electric and hybrid promises and over-the-top, 500-plus-hp, 200-mph cars close to the hearts of German engineers and executives, there was one concept at the Frankfurt auto show that actually represented a credible synthesis of green and mean: BMW's Vision EfficientDynamics. I thought it was excessively busy but highly interesting. A little to my surprise, it was the clear favorite of many serious top-level designers from other companies whose work - and opinions - I respect. But then, who wouldn't like a three-cylinder diesel that gives you, with its associated electrical helpers, 351 hp, a bunch of torque, superlow emissions, and a claimed 63 mpg?
Make an abstraction of the surface complexity and look only at the centerline profile. It is nicely proportioned and elegantly sporty, and it favorably recalls a number of equally exciting past concept cars. The transparent sides were seen on Marcello Gandini's 1966 Bertone concept - the Lamborghini Marzal - and have been recapitulated several times since, most notably by Giorgetto Giugiaro's 1972 Maserati Boomerang and 1998 Structura, as well as by Ghia for the 1977 Ford Megastar four-door. It might not be good to live with, but it's great show stuff and right at home here.
Look at the surface complexity in light of what it represents in reality. According to BMW design chief Adrian van Hooydonk, the Vision has a drag coefficient of just 0.22. That's a CFD (computational fluid dynamics) figure, not one measured in a wind tunnel, but I would be willing to bet that it is not more than five percent away from truth. Suddenly, all the hanging panels, flaps, and fences make more sense: this car is clearly related to what has been going on in Formula 1 for quite some time now - and in aviation long before that. All those little bits sticking out in the breeze direct the airflow somewhere other than where it would have gone on its own, and the flux effects positive behavioral change on the vehicle ensemble, however messy it may be to the eye.
The next time you are on a Boeing 737, look at the engine nacelle. There are some little winglike elements just behind the leading edge. They might be thought to increase drag, and indeed they do, a little, but they also result in a considerably lower landing speed. So, do the dramatic, free-floating red plastic taillight assemblies on the Vision reduce drag? I have no idea, but I suspect that they do channel the airflow in directions that are beneficial to the Vision's overall performance.
BMW's Vision is not elegant in the classical humanistic sense, but it certainly is in terms of the mathematical sense of the word, and I imagine all those admiring designers intuited that quality. The final key to a good car design lies in whether it incites a desire to drive it.
For this car? Give me the keys!