The Lotus 72 was not only the most successful single design in Formula One, it brought in design changes that even today define a Formula One car. Sidepods and engine airbox never existed until the Lotus 72. When the 72 first made it's debut in 1970, it had the nose-mounted NACA scoops.
Looking closely you can see right through one of the scoops, and this indicates that there was no ducting feeding off the scoop. It just dumped the air into the general region of the front brakes. Interestingly, I believe this is also the first instance of "chimneys", used to exit hot air coming off the brake rotors. But the car required a lot of development work before it started to enjoy success.
In 1970 aero was still evolving, ground effects had not been discovered yet. So the chassis was a simple wedge, that's all, a low drag wedge. But even that was a huge step forward. Compared to a Lotus 49 with identical engines, the 72 was 12 mph faster in a straight line, all because of the decreased drag.
I have tried to investigate as much as possible, and it appears that the NACA ducts disappeared sometime between 1970 and '71. In the original design, both front and rear shocks were mounted inboard and low. The rear shocks were overheating, and were moved outboard. My theory (so far) is that the front shocks also had overheating and the entire front end was redesigned. During this redesign process it was uncovered that the NACA ducts were no longer required. Or maybe some bright chap duct-taped over the NACA ducts and discovered no difference in brake temperatures. Somehow I believe the simpler explanation was what really happened, it usually happens this way.
What a beauty. Take your time, soak it in. Inboard brakes, pullrods, hidden shocks, and rising rate torsion bars.
This car, the Lotus 72 created a lot of history. A front driveshaft is suspected to be the cause of Rindt's fatal crash at Monza, and ever since then, engineers have been very aware about this kind of failure and it's consequences.
In five years of competition, the Lotus 72 participated in as much as 6 seasons and 74 World Championship races but most of all the car owes its fame to its record of success – 20 Grand Prix wins, 2 Drivers Championships and 3 Constructors Championship titles.
And never forget that to many, the John Player Lotus was the most beautiful of all. I am one who agrees.