I just read the article about the 640 and i was kind of shocked when reading that "The main reason for this design change was however aerodynamical, as it allowed to remove the bulky stick shift within the cockpit, along with its mechanical link to the gearbox, located at the back of the car. It allowed for a sleek nose that is so distinctive on the car."
I don't want to sound presumptuous but since this is a technical forum... well I would have expected more depth in the analysys, and much more precision. Most of the statement above is FALSE.
I was 14 years old in 1989 but the 639-640 project was right what brought me into being interested in F1. So I've read a lot about that car, i bought books and reviews, i've spoken with Luigi Mazzola (an engineer who worked with Barnard on that car for the test team) and Giorgio Piola, and I've also been lucky to see the singleseater itslef quite a few times both on track, in Monza, and in the Ferrari Museum in Maranello and at an exhibition in Florence.
The main reason John Barnard wanted to introduce a semi-authomatical gearbox was absolutely NOT aerodynamical in the first place! It was driven by a performance reason, since the shifting times could be largely reduced compared to a manual solution. An advantage that you would have seen during its debut season also in a few occasions during the starts: think about Berger at the Brazil GP or at the German one, for example. Then, saving some weight and mechanical complexity with the link from the cockpit to the rear, yes, but that was an extra benefit. Also, the opportunity for the driver to maintain both hands on the wheel for the whole time was a great asset.
About the sleek nose... that's another mistake, I am afraid. If you look at the other cars on the grid in 1989, you can see that the fact that they mounted a manual gearbox didn't prevent them to have even narrower noses than the 640. Take Benetton or Leyton House or Lotus as an example. On the contrary, the 640 nose was in a way quite large compared to most of the other cars. I think that the review misses a few other points about it: it was raised of about 5 cm with a 90 degree step underneath (more or less under the zone where the nose is attached to the chassis), and its extremity has a very distinctive shape, so that it was also known as 'The Duck' for the resemblance with the flattened animal's beak.
Also, another feature was the 640 aerodinamyc shape: the high vertical air intakes for the radiators and the vase shaped sidepods very long and quite high on the front and lowered towards the back were a breakthroguht in that era of F1 and have been copied by many other designers in the following years. The bodywork - one of the last to be still fully separated from the chassis - was said to produce a huge amount of downforce allowing the team to use very small wings at the back (compare the McLaren ones to it).
Finally, it used torsion bar suspension at the front with a scheme that again would have been copied by many engineers in the subsequent seasons.
The 640 was a masterpiece and it deserves a special place in the history of F1, despite winning just three races.
Its evolution in fact, the 641/2, came very close to win the 1990 championship.
Forgive my pedantry.
I just want to do justice to an incredible - and very good looking! - F1 car.